Apple Spotlight store database file format.asciidoc

Apple Spotlight store file formats

Summary

The Apple Spotlight store file formats are used by MacOS and iOS to store the Spotlight desktop search information. This specification is based on available source code and documentation.

This document is intended as a working document for the Apple Spotlight store file formats specification.

Document information

Author(s):	Joachim Metz <joachim.metz@gmail.com>
Abstract:	Apple Spotlight store file formats
Classification:	Public
Keywords:	Apple Spotlight store, store.db

License

Copyright (C) 2020-2024, Joachim Metz <joachim.metz@gmail.com>.
Permission is granted to copy, distribute and/or modify this document under the
terms of the GNU Free Documentation License, Version 1.3 or any later version
published by the Free Software Foundation; with no Invariant Sections, no
Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included
in the section entitled "GNU Free Documentation License".

Revision history

Version	Author	Date	Comments
0.0.1	J.B. Metz	June 2020	Initial version based on earlier notes, with thanks to Everest Munro-Zeisberger
0.0.2	J.B. Metz	June 2023	Additional changes based on format analysis
0.0.3	J.B. Metz	January 2024	Small textual changes.

1. Overview

The Apple Spotlight store file formats are used by MacOS and iOS to store the Spotlight desktop search information. This specification is based on available source code and documentation.

The Spotlight store is typically stored under:

/.Spotlight-V100/Store-V2/${UUID}/

But can also be stored in other locations such as:

/private/var/db/Spotlight-V100/BootVolume/Store-V2/${UUID}/
/Users/${USERNAME}/Library/Caches/com.apple.helpd/index.spotlightV3/
/Users/${USERNAME}/Library/Metadata/CoreSpotlight/index.spotlightV3/
/Users/${USERNAME}/Library/Developer/Xcode/DocumentationCache/v18/9.0.1/DeveloperDocumentation.index/

The Spotlight store consists of the following files:

• .store.db

• store.db

In macOS 10.15 (Catalina) the following database streams map files were added:

• dbStr-#.map.buckets

• dbStr-#.map.data

• dbStr-#.map.header

• dbStr-#.map.offsets

Characteristics	Description
Byte order	little-endian
Date and time values	Cocoa and POSIX date and time values
Character strings	UTF-8 formatted strings

1.1. Test versions

The following version of programs were used to test the information within this document:

• Mac OS X 10.7 (Lion)

• Mac OS X 10.8 (Mountain Lion)

• Mac OS X 10.9 (Mavericks)

• Mac OS X 10.10 (Yosemite)

• Mac OS X 10.11 (El Capitan)

• macOS 10.12 (Sierra)

• macOS 10.13 (High Sierra)

• macOS 10.14 (Mojave)

• macOS 10.15 (Catalina)

• macOS 11 (Big Sur)

• macOS 12 (Monterey)

• macOS 13 (Ventura)

2. Store database file

A store database (store.db) file consists of:

• file header

• map

• property tables

• metadata attribute types

• metadata attribute values

• data records

2.1. File header

The file header is at least 720 bytes in size and consists of:

Offset	Size	Value	Description
0	4	"8tsd"	Signature
4	4		Flags See section: File header flags
8	4		Unknown (0-byte values)
12	4		Unknown Seen: 0x0c
16	4		Unknown (0-byte values)
20	4		Unknown
24	4		Unknown (0-byte values)
28	4		Unknown
32	4		Unknown (0-byte values)
36	4		Map offset
40	4		Map size
44	4		Page size
48	4		Metadata attribute types (property table) block number
52	4		Metadata attribute values (property table) block number
56	4		Unknown (property table) block number
60	4		Metadata attribute lists (property table) block number
64	4		Metadata attribute localized strings (property table) block number
68	256		Unknown
324	256		Path
580	140		Unknown

The file header is stored in the first 4096 bytes

Note	The signature is "dst8" in little-endian, which cloud represention something in line of "data store".

2.1.1. File header flags

Value	Identifier	Description
0x00000001		Seen in .store.db and store.db
0x00000004		Seen in .store.db and store.db
0x00000008		Seen in .store.db
0x00000100		Seen in .store.db and store.db
0x00000400		Seen in .store.db
0x00000800		Seen in .store.db and store.db
0x00010000		Unknown (Has database streams map files)?

2.2. Pages

file offset = block number x 0x1000

2.3. Map

2.3.1. Map page header

The map page header is 20 bytes in size and consists of:

Offset	Size	Value	Description
0	4	"1mdb" "2mbd"	Signature
4	4		Page size
8	4		Number of map values
12	4		Unknown
16	4		Unknown (type?)

Note	The signature is "dbm1" or "dbm2" in little-endian, which cloud represention something in line of "database map".

2.3.2. Map page value

The map page value is 16 bytes in size and consists of:

Offset	Size	Value	Description
0	8		Unknown
8	4		Data record block number
12	4		Unknown (page size and flags?)

00001010              ab d5 00 00  00 00 00 00 19 00 00 00  |................|
00001020  00 40 00 00                                       |.@..,d......Y...|

00001020              2c 64 01 00  00 00 00 00 59 00 00 00  |.@..,d......Y...|
00001030  00 40 00 00 9c be 01 00  00 00 00 00 59 01 00 00  |.@..........Y...|
00001040  00 40 00 00 62 ca 01 00  00 00 00 00 55 00 00 00  |.@..b.......U...|
00001050  00 40 00 00 0e d2 01 00  00 00 00 00 51 00 00 00  |.@..........Q...|

TODO what about "1mbd"

2.4. Property table

2.4.1. Property table page header

The property table page header is 20 bytes in size and consists of:

Offset	Size	Value	Description
0	4	"2pbd"	Signature
4	4		Page size
8	4		Used page size Contains the size of the space in the page that is in use, which includes this header
12	4		Property table type (or flags?) See section: Property table types
16	4		Uncompressed page size Contains the size of the uncompressed page, which includes this header, or 0 if the page is not compressed

Note	The signature is "dbp2" in little-endian, which cloud represention something in line of "database property".

2.4.2. Property table types

Value	Identifier	Description
0x00000009		data records Page contains zlib+DEFLATE compressed data
0x00000011		Metadata attribute types Page contains a property table header
0x00000021		Metadata attribute values Page contains a property table header
0x00000041		Unknown Page contains a property table header
0x00000081		Metadata lists or localized strings Page contains a property table header
Flags
0x00001000		Data is LZ4 compressed
0x00004000		Unknown

2.4.3. Compressed data

Value	Identifier	Description
"\x78"		start of zlib+DEFLATE compressed data
"bv41"		LZ4 compressed block marker See section: LZ4 compressed block
"bv4-"		LZ4 uncompressed block marker See section: LZ4 uncompressed block
"bv4$"		end of LZ4 compressed stream marker

2.4.4. LZ4 compressed block

Offset	Size	Value	Description
LZ4 compressed block header
0	4	"bv41"	LZ4 compressed block marker
4	4		Uncompressed data size (in bytes)
8	4		LZ4 compressed data size (in bytes)
LZ4 compressed block data
12	…​		LZ4 compressed data

2.4.5. LZ4 uncompressed block

Offset	Size	Value	Description
0	4	"bv4-"	LZ4 uncompressed block marker
4	4		Uncompressed data size (in bytes)
LZ4 uncompressed block data
8	…​		Uncompressed data

2.4.6. Property table header

The property table header is 12 bytes of size and consists of:

Offset	Size	Value	Description
0	4		Next block offset Contains the offset of the next property table page relative to the start of the file or 0 if not set
4	8		Unknown (checksum?)

2.4.7. Data record (type 0x09)

The data record (type 0x09) is variable of size and consists of:

Offset	Size	Value	Description
0	4		Record data size
Record data
4	…​		Identifier A variable size integer that contains the file system identifier, e.g. CNID on HFS, of the corresponding file (system) entry
…​	1		Data record flags See section: Data record flags
…​	…​		Item identifier Contains a variable size integer
…​	…​		Parent identifier A variable size integer that contains the file system identifier, e.g. CNID on HFS, of the parent file (system) entry
…​	…​		Last updated time Contains a variable size integer that contains the number of microseconds since January 1, 1970 00:00:00 Assuming this is UTC
…​	…​		Properties array

2.4.8. Data record flags

Value	Identifier	Description
0x01		Unknown (Is metadata?) Seen in record with identifier 0
0x02
0x10
0x20
0x40

TODO: describe property

Offset	Size	Value	Description
0	…​		Property data size Contains a variable size integer

2.4.9. Metadata attribute types property table (type 0x11) value

The metadata attribute types property table (type 0x11) value is variable of size and consists of:

Offset	Size	Value	Description
0	4		Table index
4	1		Value type See section: Metadata attribute value types
5	1		Property type
6	…​		Key name Contains an UTF-8 encoded string with an end-of-string character

2.4.10. Metadata attribute values property table (type 0x21) value

The metadata attribute values property table (type 0x21) value is variable of size and consists of:

Offset	Size	Value	Description
0	4		Table index
4	…​		Metadata attribute value name Contains an UTF-8 encoded string with an end-of-string character

Note	Some value names contain "\x16\x02" (SYN, STX), followed by a language identifier.

2.4.11. Unknown property table (type 0x41) value

0x00000000  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  ................
...
0x00003fd0  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  ................

2.4.12. Metadata lists or localized strings property table (type 0x81) value

The metadata lists or localized strings property table (type 0x81) value is variable of size and consists of:

Offset	Size	Value	Description
0	4		Table index
4	…​		Index data size Contains a variable size integer
Index data
…​	…​		Unknown (Index data padding?) If the index data size is not a multitude of 4 (32-bit) additional bytes are stored before the index array
…​	…​		Index array Contains an array of 32-bit integer values

2.5. Metadata attributes

The metadata attributes are stored using several property tables.

• The metadata attribute types table, contain the key names, value types and property types of the metadata attributes

• The metadata attribute values table, contains the values used by the metadata attributes

• The metadata attribute lists table, contains the lists of values used by the metadata attributes

• The metadata attribute localized string table, contains the lists of localized string values used by the metadata attributes

2.5.1. Metadata attribute value types

Value	Identifier	Description
0x00		Boolean Contains a variable size integer See section: Variable-size integer
0x01		Unknown
0x02		Unknown Contains a variable size integer See section: Variable-size integer Seen in combination with "_kMDItemGroupId"
0x03		Unknown
0x04		Unknown
0x05		Unknown
0x06		Unknown Contains a variable size integer See section: Variable-size integer Seen in combination with "_kStoreMetadataVersion"
0x07		Variable-size integer See section: Variable-size integer If the 2nd LSB of the property type is set the value data contains a multi-value. See section Multi-value
0x08		Unknown (Byte or 8-bit integer)
0x09		Floating-point 32-bit If the 2nd LSB of the property type is set the value data contains a multi-value. See section Multi-value
0x0a		Floating-point 64-bit If the 2nd LSB of the property type is set the value data contains a multi-value. See section Multi-value
0x0b		String Contains strings data See section: Strings data The 2 LSB of the property type indicate if the value is a list of localized strings (0x3), list of strings (0x2) or single string (0x1, 0x0)
0x0c		Date and time Contains a floating-point 64-bit values of a Cocoa timestamp If the 2nd LSB of the property type is set the value data contains a multi-value. See section Multi-value
0x0e		Binary data See section: Binary data
0x0f		Metadata attribute value or list reference The 2 LSB of the property type indicate if the value references a localized string (0x3), list (0x2) or value (0x1) type

2.5.2. Variable-size integer

TODO: add description

2.5.3. Multi-value

Offset	Size	Value	Description
0	…​		Values data size Contains a variable size integer
…​	…​		Values data Contains data dependent on the value type

2.5.4. Strings data

Offset	Size	Value	Description
0	…​		Strings data size Contains a variable size integer
…​	…​		Strings data Contains one or more UTF-8 encoded strings with an end-of-string character

2.5.5. Binary data

Offset	Size	Value	Description
0	…​		Binary data size Contains a variable size integer
…​	…​		Binary data

2.6. Metadata item (MDItem)

2.6.1. Metadata item 0x01

Metadata attributes:

Value	Property type	Value type	Description
_kStoreMetadataVersion	0x0c	0x06	Contains a 32-bit integer with version information where the upper 16-bit contains the major version and the lower 16-bit the minor version, for example 0x0001000d represents "1.13"
kMDStoreProperties	0x0c	0x0e	Contains a XML plist
kMDStoreUUID	0x0c	0x0e	Contains the store UUID Is the UUID stored in big-endian?
kMDStoreAccumulatedSizes	0x0e	0x08	Unknown, does not follow the normal behavior of value type 0x08, could this be due to flags 0x01?

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
        <key>CabGroupsConverted</key>
        <string>23</string>
        <key>MLMailFlagsFixUp</key>
        <string>14F27</string>
        <key>MLMailReadFixUp</key>
        <string>14F27</string>
        <key>MLReimportedApps</key>
        <true/>
        <key>MLReimportedChats</key>
        <true/>
        <key>MLReimportedFailures</key>
        <string>14F27</string>
        <key>MLReimportedMail</key>
        <true/>
        <key>ReimportedAltNames</key>
        <string>14F27</string>
        <key>ReimportedPhotoLibraries</key>
        <true/>
        <key>SDBConsistencyCheck</key>
        <string>14F27</string>
        <key>database.diskstoreversion</key>
        <integer>2</integer>
        <key>database.fseventsuuid</key>
        <string>B3F639AD-3C93-4970-9D7E-EAD2B0875FDA</string>
        <key>database.fullyindexbysnowleopard</key>
        <true/>
        <key>database.localizedtermsuuid</key>
        <data>
        9RsNbp5KQI+fBJGSuOkzSQ==
        </data>
        <key>database.recoverscantime</key>
        <integer>1442686011</integer>
        <key>database.shutdowntime</key>
        <integer>1440532242</integer>
        <key>database.volumeuuid</key>
        <string>8C76D365-800A-3B5C-8320-55C3E6032D70</string>
        <key>kCabReimportedMail</key>
        <true/>
        <key>kIndexCheckDupOids</key>
        <string>14F27</string>
        <key>kIndexRemappingData</key>
        <key>kIndexRemappingData</key>
        <dict>
                <key>kIndexRemappingIndex</key>
                <integer>4</integer>
                <key>kIndexRemappings</key>
                <array/>
        </dict>
        <key>kMDSIndexSyncCount</key>
        <integer>41</integer>
        <key>kSIConsistencyCheck</key>
        <string>14F27</string>
        <key>kSIRepairSizes</key>
        <string>14F27</string>
        <key>kSIRepairedIndex</key>
        <true/>
        <key>scan.fullscancomplete</key>
        <true/>
        <key>scan.fullscanrequesttime</key>
        <integer>1435155044</integer>
        <key>scan.scancompletetime</key>
        <integer>1435157167</integer>
</dict>
</plist>

Metadata attribute: 3 type index                                        : 21
Key name                                                                : kMDStoreAccumulatedSizes
Property type                                                           : 0x0e
Value type                                                              : 0x08
Data:
0x00000000  80 98 00 e0 30 a2 44 c0  50 00 f0 25 18 20 00 f0  ....0.D.P..%. ..
0x00000010  3b ae 04 e0 d9 c0 00 83  1b e2 ca d0 00 f3 66 f6  ;.............f.
0x00000020  40 00 00 e3 a6 9e 00 e2  22 91 28 c0 5e 74 f0 37  @.......".(.^t.7
0x00000030  e5 a8 81 e4 7a 42 c3 f0  38 6f 18 7e a2 00 00 f0  ....zB..8o.~....

Metadata attribute: 3 type index                                        : 67
Key name                                                                : kMDStoreAccumulatedSizes
Property type                                                           : 0x0e
Value type                                                              : 0x08
Data:
0x00000000  80 98 00 00 a0 00 e5 67  20 00 f0 1f 9d 11 44 00  .......g .....D.
0x00000010  83 1b f0 12 5a c0 00 f0  ae f4 31 6d 00 f0 52 fc  ....Z.....1m..R.
0x00000020  0a 60 e3 8d df 39 c1 07  3a f0 45 57 00 f8 ea 2f  .`...9..:.EW.../
0x00000030  23 54 f0 81 cc d2 e2 a2  00 00 f8 0a              #T..........

Relative metadata attribute: 3 type index                               : 1
Metadata attribute: 3 type index                                        : 23
Key name                                                                : kMDStoreAccumulatedSizes
Property type                                                           : 0x0e
Value type                                                              : 0x08
Data:
0x00000000  80 88 00 00 00 00 00 00  00 00 00 00 00 00 00     ...............

2.6.2. Metadata item

Value	Property type	Value type	Description
_kMDItemAppStoreRefID
_kMDItemContentChangeDate		0x0c
_kMDItemCreationDate		0x0c	Creation date and time of the corresponding file (system) entry?
_kMDItemCreatorCode		0x07
_kMDItemFileName		0x0b	Name of the corresponding file (system) entry
_kMDItemFinderExcluded		0x00
_kMDItemFinderFlags		0x07
_kMDItemFinderLabel		0x07
_kMDItemGroupId		0x02
_kMDItemImporterResult
_kMDItemIndexedByBackup
_kMDItemIsExtensionHidden		0x00
_kMDItemLocked
_kMDItemNodeCount
_kMDItemOwnerGroupID		0x07
_kMDItemOwnerUserID		0x07
_kMDItemPrescanCandidate
_kMDItemSizingIsNeeded
_kMDItemStaticInterestScore		0x09
_kMDItemTextContentIndexExists
_kMDItemTextEncodingHint
_kMDItemTimeMachinePath
_kMDItemTypeCode		0x07
_kMDItemUpgraded
_kMDXXXX___DUMMY`
_kTimeMachineNewestSnapshot		0x0c
_kTimeMachineOldestSnapshot		0x0c
com_apple_ats_name_family
com_apple_ats_name_fond
com_apple_ats_name_full
com_apple_ats_name_postscript
com_apple_ats_names
com_apple_ats_name_style
com_apple_backup_excludeItem
com_apple_iCal_Bookmark_FullDay
com_apple_iCal_Bookmark_SharedUID
com_apple_mail_attachmentKinds
com_apple_mail_attachmentNames
com_apple_mail_attachmentSpecificTypes
com_apple_mail_attachmentTypes
com_apple_mail_dateLastViewed
com_apple_mail_dateReceived
com_apple_mail_flagged
com_apple_mail_messageID
com_apple_mail_priority
com_apple_mail_read
com_apple_mail_repliedTo
com_apple_system_prefs_keywords
kMDItemAlternateNames
kMDItemAppStoreAdamID
kMDItemAppStoreCategory
kMDItemAppStoreCategoryType
kMDItemAppStoreHasReceipt
kMDItemAppStoreInstallerVersionID
kMDItemAppStoreIsAppleSigned
kMDItemAppStorePurchaseDate		0x0c
kMDItemAppStoreReceiptIsRevoked
kMDItemAppStoreReceiptIsVPPLicensed
kMDItemAppStoreReceiptType
kMDItemAttributeChangeDate
kMDItemAudioBitRate
kMDItemAudioChannelCount
kMDItemAudioSampleRate
kMDItemAuthorEmailAddresses
kMDItemAuthors
kMDItemBitsPerSample
kMDItemCFBundleIdentifier
kMDItemCity
kMDItemColorSpace
kMDItemComment
kMDItemContentCreationDate		0x0c
kMDItemContentModificationDate		0x0c
kMDItemContentType		0x0f	Value string
kMDItemContentTypeTree		0x0f	Value list
kMDItemCopyright
kMDItemCountry
kMDItemCoverage
kMDItemCreator
kMDItemDateAdded		0x09
kMDItemDisplayName		0x0b
kMDItemDownloadedDate	0x0c		kMDItemDurationSeconds
			kMDItemEditors
			kMDItemEncodingApplications
			kMDItemExecutableArchitectures
			kMDItemFonts
			kMDItemHasAlphaChannel
			kMDItemInvisibleFileType
			kMDItemIsApplicationManaged
			kMDItemIsLikelyJunk
			kMDItemKeywords
			kMDItemKind
	0x0f	Localized string	kMDItemLanguages
			kMDItemLastUsedDate
	0x0c		kMDItemLogicalSize
	0x07		kMDItemMediaTypes
			kMDItemNumberOfPages
			kMDItemOrientation
			kMDItemPageHeight
			kMDItemPageWidth
			kMDItemPhoneNumbers
			kMDItemPhysicalSize
	0x07		kMDItemPixelCount
			kMDItemPixelHeight
			kMDItemPixelWidth
			kMDItemProfileName
			kMDItemPublishers
			kMDItemRecipientEmailAddresses
			kMDItemRecipients
			kMDItemResolutionHeightDPI
			kMDItemResolutionWidthDPI
			kMDItemSecurityMethod
			kMDItemStateOrProvince
			kMDItemSubject
			kMDItemSupportFileType
			kMDItemTitle
			kMDItemTotalBitRate
			kMDItemURL
			kMDItemURL
	0x0b		kMDItemUseCount
			kMDItemUsedDates
0x0c	Contains an array of date and time values	kMDItemVersion
		kMDItemWhereFroms

3. Database streams map (dbStr-#.map) files

The # in the filename corresponds to the nature of the strings in the map.

Value	Identifier	Description
1		Metadata types streams map
2		Metadata values streams map
3		Unknown values 0x41 streams map
4		Metadata lists streams map
5		Metadata localized strings streams map

3.1. Database streams map header file (dbStr-#.map.header)

The database streams map header file (dbStr-#.map.header) file is 56 bytes in size and consists of:

Offset	Size	Value	Description
0	8	"\x00PataD\x00\x00"	Signature
8	4		Unknown (Seen: 13)
12	4		Unknown (Seen: 0, 2 in dbStr-1.map.header)
16	4		Unknown (Seen: 1)
20	4		Size of the data in the corresponding dbStr-#.map.data file
24	4		Number of entries in the corresponding dbStr-#.map.buckets file
28	4		Number of entries in the corresponding dbStr-#.map.ofsets file
32	4		Unknown (copy of value at offset 20?)
36	4		Unknown (copy of value at offset 24?)
40	4		Unknown (copy of value at offset 28?)
44	4	0	Unknown (empty)
48	4	0	Unknown (empty)
52	4	0	Unknown (empty)

3.2. Database streams map offsets file (dbStr-#.map.offsets)

The database streams map offsets file (dbStr-#.map.offsets) file is variable of size and consists of:

Offset	Size	Value	Description
0	4 x number of entries		Array of 32-bit offsets The offset of the value in the corresponding dbStr-#.map.data file
…​	…​	0	Unknown (empty)

The size of corresponding stream value is calculated as:

size = next offset or data size - current offset

3.3. Database streams map data file (dbStr-#.map.data)

The database streams map data file (dbStr-#.map.data) is variable of size and consists of:

• One or more stream values

Note	Note that the first stream value always appears to be a single 0-byte value.

A stream value is variable of size and consists of:

Offset	Size	Value	Description
0	…​		Stream value data

3.3.1. Metadata attribute types

The dbStr-1.map.data file contains metadata attribute types that consist of:

Offset	Size	Value	Description
0	…​		Unknown (stream value data size) See section: Variable-size integer
…​	1		Value type See section: Metadata attribute value types
…​	1		Property type
…​	…​		Key name Contains an UTF-8 encoded string with an end-of-string character

3.3.2. Metadata attribute values

The dbStr-2.map.data file contains metadata attribute values that consist of:

Offset	Size	Value	Description
0	…​		Unknown (stream value data size) See section: Variable-size integer
…​	…​		Metadata attribute value name Contains an UTF-8 encoded string with an end-of-string character

3.3.3. Index values

The dbStr-3.map.data, dbStr-4.map.data and dbStr-5.map.data files contains metadata attribute values that consist of:

Offset	Size	Value	Description
0	…​		Unknown See section: Variable-size integer
…​	…​		Index data size Contains a variable size integer
…​	…​		Index array Contains an array of 32-bit integer values

3.4. Database streams map buckets file (dbStr-#.map.buckets)

The database streams map buckets file (dbStr-#.map.buckets) file is variable of size and consists of:

Offset	Size	Value	Description
0	4 x number of entries		Array of 32-bit offsets TODO:Relates to an index in the corresponding dbStr-#.map.offsets file?
…​	…​	0	Unknown (empty)

4. Notes

/.Spotlight-V100/Store-V2/${STORE_UUID}/store.updates
/.Spotlight-V100/Store-V2/${STORE_UUID}/store_generation

Appendix A: References

[REFERENCE]

Title:	Common Metadata Attribute Keys
Author(s):	Apple Inc.
URL:	https://developer.apple.com/documentation/coreservices/file_metadata/mditem/common_metadata_attribute_keys

Appendix B: GNU Free Documentation License

Version 1.3, 3 November 2008 Copyright © 2000, 2001, 2002, 2007, 2008 Free Software Foundation, Inc. http://fsf.org/

Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed.

0. PREAMBLE

The purpose of this License is to make a manual, textbook, or other functional and useful document "free" in the sense of freedom: to assure everyone the effective freedom to copy and redistribute it, with or without modifying it, either commercially or noncommercially. Secondarily, this License preserves for the author and publisher a way to get credit for their work, while not being considered responsible for modifications made by others.

This License is a kind of "copyleft", which means that derivative works of the document must themselves be free in the same sense. It complements the GNU General Public License, which is a copyleft license designed for free software.

We have designed this License in order to use it for manuals for free software, because free software needs free documentation: a free program should come with manuals providing the same freedoms that the software does. But this License is not limited to software manuals; it can be used for any textual work, regardless of subject matter or whether it is published as a printed book. We recommend this License principally for works whose purpose is instruction or reference.

1. APPLICABILITY AND DEFINITIONS

This License applies to any manual or other work, in any medium, that contains a notice placed by the copyright holder saying it can be distributed under the terms of this License. Such a notice grants a world-wide, royalty-free license, unlimited in duration, to use that work under the conditions stated herein. The "Document", below, refers to any such manual or work. Any member of the public is a licensee, and is addressed as "you". You accept the license if you copy, modify or distribute the work in a way requiring permission under copyright law.

A "Modified Version" of the Document means any work containing the Document or a portion of it, either copied verbatim, or with modifications and/or translated into another language.

A "Secondary Section" is a named appendix or a front-matter section of the Document that deals exclusively with the relationship of the publishers or authors of the Document to the Document’s overall subject (or to related matters) and contains nothing that could fall directly within that overall subject. (Thus, if the Document is in part a textbook of mathematics, a Secondary Section may not explain any mathematics.) The relationship could be a matter of historical connection with the subject or with related matters, or of legal, commercial, philosophical, ethical or political position regarding them.

The "Invariant Sections" are certain Secondary Sections whose titles are designated, as being those of Invariant Sections, in the notice that says that the Document is released under this License. If a section does not fit the above definition of Secondary then it is not allowed to be designated as Invariant. The Document may contain zero Invariant Sections. If the Document does not identify any Invariant Sections then there are none.

The "Cover Texts" are certain short passages of text that are listed, as Front-Cover Texts or Back-Cover Texts, in the notice that says that the Document is released under this License. A Front-Cover Text may be at most 5 words, and a Back-Cover Text may be at most 25 words.

A "Transparent" copy of the Document means a machine-readable copy, represented in a format whose specification is available to the general public, that is suitable for revising the document straightforwardly with generic text editors or (for images composed of pixels) generic paint programs or (for drawings) some widely available drawing editor, and that is suitable for input to text formatters or for automatic translation to a variety of formats suitable for input to text formatters. A copy made in an otherwise Transparent file format whose markup, or absence of markup, has been arranged to thwart or discourage subsequent modification by readers is not Transparent. An image format is not Transparent if used for any substantial amount of text. A copy that is not "Transparent" is called "Opaque".

Examples of suitable formats for Transparent copies include plain ASCII without markup, Texinfo input format, LaTeX input format, SGML or XML using a publicly available DTD, and standard-conforming simple HTML, PostScript or PDF designed for human modification. Examples of transparent image formats include PNG, XCF and JPG. Opaque formats include proprietary formats that can be read and edited only by proprietary word processors, SGML or XML for which the DTD and/or processing tools are not generally available, and the machine-generated HTML, PostScript or PDF produced by some word processors for output purposes only.

The "Title Page" means, for a printed book, the title page itself, plus such following pages as are needed to hold, legibly, the material this License requires to appear in the title page. For works in formats which do not have any title page as such, "Title Page" means the text near the most prominent appearance of the work’s title, preceding the beginning of the body of the text.

The "publisher" means any person or entity that distributes copies of the Document to the public.

A section "Entitled XYZ" means a named subunit of the Document whose title either is precisely XYZ or contains XYZ in parentheses following text that translates XYZ in another language. (Here XYZ stands for a specific section name mentioned below, such as "Acknowledgements", "Dedications", "Endorsements", or "History".) To "Preserve the Title" of such a section when you modify the Document means that it remains a section "Entitled XYZ" according to this definition.

The Document may include Warranty Disclaimers next to the notice which states that this License applies to the Document. These Warranty Disclaimers are considered to be included by reference in this License, but only as regards disclaiming warranties: any other implication that these Warranty Disclaimers may have is void and has no effect on the meaning of this License.

2. VERBATIM COPYING

You may copy and distribute the Document in any medium, either commercially or noncommercially, provided that this License, the copyright notices, and the license notice saying this License applies to the Document are reproduced in all copies, and that you add no other conditions whatsoever to those of this License. You may not use technical measures to obstruct or control the reading or further copying of the copies you make or distribute. However, you may accept compensation in exchange for copies. If you distribute a large enough number of copies you must also follow the conditions in section 3.

You may also lend copies, under the same conditions stated above, and you may publicly display copies.

3. COPYING IN QUANTITY

If you publish printed copies (or copies in media that commonly have printed covers) of the Document, numbering more than 100, and the Document’s license notice requires Cover Texts, you must enclose the copies in covers that carry, clearly and legibly, all these Cover Texts: Front-Cover Texts on the front cover, and Back-Cover Texts on the back cover. Both covers must also clearly and legibly identify you as the publisher of these copies. The front cover must present the full title with all words of the title equally prominent and visible. You may add other material on the covers in addition. Copying with changes limited to the covers, as long as they preserve the title of the Document and satisfy these conditions, can be treated as verbatim copying in other respects.

If the required texts for either cover are too voluminous to fit legibly, you should put the first ones listed (as many as fit reasonably) on the actual cover, and continue the rest onto adjacent pages.

If you publish or distribute Opaque copies of the Document numbering more than 100, you must either include a machine-readable Transparent copy along with each Opaque copy, or state in or with each Opaque copy a computer-network location from which the general network-using public has access to download using public-standard network protocols a complete Transparent copy of the Document, free of added material. If you use the latter option, you must take reasonably prudent steps, when you begin distribution of Opaque copies in quantity, to ensure that this Transparent copy will remain thus accessible at the stated location until at least one year after the last time you distribute an Opaque copy (directly or through your agents or retailers) of that edition to the public.

It is requested, but not required, that you contact the authors of the Document well before redistributing any large number of copies, to give them a chance to provide you with an updated version of the Document.

4. MODIFICATIONS

You may copy and distribute a Modified Version of the Document under the conditions of sections 2 and 3 above, provided that you release the Modified Version under precisely this License, with the Modified Version filling the role of the Document, thus licensing distribution and modification of the Modified Version to whoever possesses a copy of it. In addition, you must do these things in the Modified Version:

1. Use in the Title Page (and on the covers, if any) a title distinct from that of the Document, and from those of previous versions (which should, if there were any, be listed in the History section of the Document). You may use the same title as a previous version if the original publisher of that version gives permission.

2. List on the Title Page, as authors, one or more persons or entities responsible for authorship of the modifications in the Modified Version, together with at least five of the principal authors of the Document (all of its principal authors, if it has fewer than five), unless they release you from this requirement.

3. State on the Title page the name of the publisher of the Modified Version, as the publisher.

4. Preserve all the copyright notices of the Document.

5. Add an appropriate copyright notice for your modifications adjacent to the other copyright notices.

6. Include, immediately after the copyright notices, a license notice giving the public permission to use the Modified Version under the terms of this License, in the form shown in the Addendum below.

7. Preserve in that license notice the full lists of Invariant Sections and required Cover Texts given in the Document’s license notice.

8. Include an unaltered copy of this License.

9. Preserve the section Entitled "History", Preserve its Title, and add to it an item stating at least the title, year, new authors, and publisher of the Modified Version as given on the Title Page. If there is no section Entitled "History" in the Document, create one stating the title, year, authors, and publisher of the Document as given on its Title Page, then add an item describing the Modified Version as stated in the previous sentence.

10. Preserve the network location, if any, given in the Document for public access to a Transparent copy of the Document, and likewise the network locations given in the Document for previous versions it was based on. These may be placed in the "History" section. You may omit a network location for a work that was published at least four years before the Document itself, or if the original publisher of the version it refers to gives permission.

11. For any section Entitled "Acknowledgements" or "Dedications", Preserve the Title of the section, and preserve in the section all the substance and tone of each of the contributor acknowledgements and/or dedications given therein.

12. Preserve all the Invariant Sections of the Document, unaltered in their text and in their titles. Section numbers or the equivalent are not considered part of the section titles.

13. Delete any section Entitled "Endorsements". Such a section may not be included in the Modified Version.

14. Do not retitle any existing section to be Entitled "Endorsements" or to conflict in title with any Invariant Section.

15. Preserve any Warranty Disclaimers.

If the Modified Version includes new front-matter sections or appendices that qualify as Secondary Sections and contain no material copied from the Document, you may at your option designate some or all of these sections as invariant. To do this, add their titles to the list of Invariant Sections in the Modified Version’s license notice. These titles must be distinct from any other section titles.

You may add a section Entitled "Endorsements", provided it contains nothing but endorsements of your Modified Version by various parties—for example, statements of peer review or that the text has been approved by an organization as the authoritative definition of a standard.

You may add a passage of up to five words as a Front-Cover Text, and a passage of up to 25 words as a Back-Cover Text, to the end of the list of Cover Texts in the Modified Version. Only one passage of Front-Cover Text and one of Back-Cover Text may be added by (or through arrangements made by) any one entity. If the Document already includes a cover text for the same cover, previously added by you or by arrangement made by the same entity you are acting on behalf of, you may not add another; but you may replace the old one, on explicit permission from the previous publisher that added the old one.

The author(s) and publisher(s) of the Document do not by this License give permission to use their names for publicity for or to assert or imply endorsement of any Modified Version.

5. COMBINING DOCUMENTS

You may combine the Document with other documents released under this License, under the terms defined in section 4 above for modified versions, provided that you include in the combination all of the Invariant Sections of all of the original documents, unmodified, and list them all as Invariant Sections of your combined work in its license notice, and that you preserve all their Warranty Disclaimers.

The combined work need only contain one copy of this License, and multiple identical Invariant Sections may be replaced with a single copy. If there are multiple Invariant Sections with the same name but different contents, make the title of each such section unique by adding at the end of it, in parentheses, the name of the original author or publisher of that section if known, or else a unique number. Make the same adjustment to the section titles in the list of Invariant Sections in the license notice of the combined work.

In the combination, you must combine any sections Entitled "History" in the various original documents, forming one section Entitled "History"; likewise combine any sections Entitled "Acknowledgements", and any sections Entitled "Dedications". You must delete all sections Entitled "Endorsements".

6. COLLECTIONS OF DOCUMENTS

You may make a collection consisting of the Document and other documents released under this License, and replace the individual copies of this License in the various documents with a single copy that is included in the collection, provided that you follow the rules of this License for verbatim copying of each of the documents in all other respects.

You may extract a single document from such a collection, and distribute it individually under this License, provided you insert a copy of this License into the extracted document, and follow this License in all other respects regarding verbatim copying of that document.

7. AGGREGATION WITH INDEPENDENT WORKS

A compilation of the Document or its derivatives with other separate and independent documents or works, in or on a volume of a storage or distribution medium, is called an "aggregate" if the copyright resulting from the compilation is not used to limit the legal rights of the compilation’s users beyond what the individual works permit. When the Document is included in an aggregate, this License does not apply to the other works in the aggregate which are not themselves derivative works of the Document.

If the Cover Text requirement of section 3 is applicable to these copies of the Document, then if the Document is less than one half of the entire aggregate, the Document’s Cover Texts may be placed on covers that bracket the Document within the aggregate, or the electronic equivalent of covers if the Document is in electronic form. Otherwise they must appear on printed covers that bracket the whole aggregate.

8. TRANSLATION

Translation is considered a kind of modification, so you may distribute translations of the Document under the terms of section 4. Replacing Invariant Sections with translations requires special permission from their copyright holders, but you may include translations of some or all Invariant Sections in addition to the original versions of these Invariant Sections. You may include a translation of this License, and all the license notices in the Document, and any Warranty Disclaimers, provided that you also include the original English version of this License and the original versions of those notices and disclaimers. In case of a disagreement between the translation and the original version of this License or a notice or disclaimer, the original version will prevail.

If a section in the Document is Entitled "Acknowledgements", "Dedications", or "History", the requirement (section 4) to Preserve its Title (section 1) will typically require changing the actual title.

9. TERMINATION

You may not copy, modify, sublicense, or distribute the Document except as expressly provided under this License. Any attempt otherwise to copy, modify, sublicense, or distribute it is void, and will automatically terminate your rights under this License.

However, if you cease all violation of this License, then your license from a particular copyright holder is reinstated (a) provisionally, unless and until the copyright holder explicitly and finally terminates your license, and (b) permanently, if the copyright holder fails to notify you of the violation by some reasonable means prior to 60 days after the cessation.

Moreover, your license from a particular copyright holder is reinstated permanently if the copyright holder notifies you of the violation by some reasonable means, this is the first time you have received notice of violation of this License (for any work) from that copyright holder, and you cure the violation prior to 30 days after your receipt of the notice.

Termination of your rights under this section does not terminate the licenses of parties who have received copies or rights from you under this License. If your rights have been terminated and not permanently reinstated, receipt of a copy of some or all of the same material does not give you any rights to use it.

10. FUTURE REVISIONS OF THIS LICENSE

The Free Software Foundation may publish new, revised versions of the GNU Free Documentation License from time to time. Such new versions will be similar in spirit to the present version, but may differ in detail to address new problems or concerns. See http://www.gnu.org/copyleft/.

Each version of the License is given a distinguishing version number. If the Document specifies that a particular numbered version of this License "or any later version" applies to it, you have the option of following the terms and conditions either of that specified version or of any later version that has been published (not as a draft) by the Free Software Foundation. If the Document does not specify a version number of this License, you may choose any version ever published (not as a draft) by the Free Software Foundation. If the Document specifies that a proxy can decide which future versions of this License can be used, that proxy’s public statement of acceptance of a version permanently authorizes you to choose that version for the Document.

11. RELICENSING

"Massive Multiauthor Collaboration Site" (or "MMC Site") means any World Wide Web server that publishes copyrightable works and also provides prominent facilities for anybody to edit those works. A public wiki that anybody can edit is an example of such a server. A "Massive Multiauthor Collaboration" (or "MMC") contained in the site means any set of copyrightable works thus published on the MMC site.

"CC-BY-SA" means the Creative Commons Attribution-Share Alike 3.0 license published by Creative Commons Corporation, a not-for-profit corporation with a principal place of business in San Francisco, California, as well as future copyleft versions of that license published by that same organization.

"Incorporate" means to publish or republish a Document, in whole or in part, as part of another Document.

An MMC is "eligible for relicensing" if it is licensed under this License, and if all works that were first published under this License somewhere other than this MMC, and subsequently incorporated in whole or in part into the MMC, (1) had no cover texts or invariant sections, and (2) were thus incorporated prior to November 1, 2008.

The operator of an MMC Site may republish an MMC contained in the site under CC-BY-SA on the same site at any time before August 1, 2009, provided the MMC is eligible for relicensing.