diff --git a/R/ansiex.R b/R/ansiex.R
index 9369db86..b0155f30 100644
--- a/R/ansiex.R
+++ b/R/ansiex.R
@@ -151,9 +151,11 @@ ansi_nchar <- function(
 #' Substring(s) of an ANSI colored string
 #'
 #' This is a color-aware counterpart of [base::substr()].
-#' It works exactly like the original, but keeps the colors
+#' It works like the original, but keeps the colors
 #' in the substrings. The ANSI escape sequences are ignored when
 #' calculating the positions within the string.
+#' Unlike [base::substr()], the replacement form
+#' (`ansi_substr(x, start, stop) <- value`) is not supported.
 #'
 #' @param x Character vector, potentially ANSI styled, or a vector to
 #'   coerced to character.
@@ -236,9 +238,11 @@ ansi_substr <- function(x, start, stop) {
 #' Substring(s) of an ANSI colored string
 #'
 #' This is the color-aware counterpart of [base::substring()].
-#' It works exactly like the original, but keeps the colors in the
+#' It works like the original, but keeps the colors in the
 #' substrings. The ANSI escape sequences are ignored when
 #' calculating the positions within the string.
+#' Unlike [base::substring()], the replacement form
+#' (`substring(text, first, last) <- value`) is not supported.
 #'
 #' @param text Character vector, potentially ANSI styled, or a vector to
 #'   coerced to character. It is recycled to the longest of `first`
diff --git a/R/bullets.R b/R/bullets.R
index 008d1071..86e47055 100644
--- a/R/bullets.R
+++ b/R/bullets.R
@@ -70,7 +70,7 @@ cli_bullets <- function(
 
 #' List of verbatim items
 #'
-#' `cli_format_bullets_raw()` is similar to [cli_bullets()], but it does
+#' `cli_bullets_raw()` is similar to [cli_bullets()], but it does
 #' not perform any inline styling or glue substitutions in the input.
 #'
 #' `format_bullets_raw()` returns the output instead of printing it.
diff --git a/R/format-conditions.R b/R/format-conditions.R
index 645c81fc..3de3416d 100644
--- a/R/format-conditions.R
+++ b/R/format-conditions.R
@@ -26,6 +26,7 @@
 #' @param message It is formatted via a call to [cli_bullets()].
 #' @param .envir Environment to evaluate the glue expressions in.
 #'
+#' @return A character string containing the formatted message.
 #' @seealso These functions support [inline markup][inline-markup].
 #' @family functions supporting inline markup
 #' @export
diff --git a/R/ruler.R b/R/ruler.R
index e19537d9..a3476b62 100644
--- a/R/ruler.R
+++ b/R/ruler.R
@@ -1,5 +1,7 @@
 #' Print the helpful ruler to the screen
 #'
+#' @return `NULL`, invisibly. Called for its side effect of printing a
+#'   ruler to the screen.
 #' @export
 #' @param width Ruler width.
 #' @examples
diff --git a/R/simple-theme.R b/R/simple-theme.R
index d903b0f7..e656688b 100644
--- a/R/simple-theme.R
+++ b/R/simple-theme.R
@@ -60,6 +60,7 @@
 #'   Detection usually works in recent RStudio versions, and in iTerm
 #'   on macOS, but not on other platforms.
 #'
+#' @return A named list that can be used as a cli theme.
 #' @seealso [themes], [builtin_theme()].
 #' @export
 
diff --git a/R/spark.R b/R/spark.R
index bd37c8fc..aa5e3b57 100644
--- a/R/spark.R
+++ b/R/spark.R
@@ -34,6 +34,7 @@
 #' ```
 #'
 #' @param x A numeric vector between 0 and 1
+#' @return A character string of class `cli_spark_bar` and `cli_spark`.
 #' @export
 #' @seealso [spark_line()]
 
@@ -95,6 +96,7 @@ spark_bar_chars <- function(x, bars = NULL) {
 #' ```
 #'
 #' @inheritParams spark_bar
+#' @return A character string of class `cli_spark_line` and `cli_spark`.
 #' @export
 #' @seealso [spark_bar()]
 
diff --git a/R/test.R b/R/test.R
index babde53a..d2d488ee 100644
--- a/R/test.R
+++ b/R/test.R
@@ -41,6 +41,8 @@
 #'   * `"all"`: turn on all hyperlinks,
 #'   * `"none"`: turn off all hyperlinks.
 #'
+#' @return The return value of [testthat::test_that()] for the last
+#'   configuration tested (invisibly).
 #' @export
 #' @examples
 #' # testthat cannot record or compare snapshots when you run these
diff --git a/man/ansi_substr.Rd b/man/ansi_substr.Rd
index f2ec9e26..fb37a589 100644
--- a/man/ansi_substr.Rd
+++ b/man/ansi_substr.Rd
@@ -22,9 +22,11 @@ the requested substrings. ANSI styles are retained.
 }
 \description{
 This is a color-aware counterpart of \code{\link[base:substr]{base::substr()}}.
-It works exactly like the original, but keeps the colors
+It works like the original, but keeps the colors
 in the substrings. The ANSI escape sequences are ignored when
 calculating the positions within the string.
+Unlike \code{\link[base:substr]{base::substr()}}, the replacement form
+(\code{ansi_substr(x, start, stop) <- value}) is not supported.
 }
 \examples{
 str <- paste(
diff --git a/man/ansi_substring.Rd b/man/ansi_substring.Rd
index a37fd891..48dd7b98 100644
--- a/man/ansi_substring.Rd
+++ b/man/ansi_substring.Rd
@@ -23,9 +23,11 @@ the requested substrings. ANSI styles are retained.
 }
 \description{
 This is the color-aware counterpart of \code{\link[base:substring]{base::substring()}}.
-It works exactly like the original, but keeps the colors in the
+It works like the original, but keeps the colors in the
 substrings. The ANSI escape sequences are ignored when
 calculating the positions within the string.
+Unlike \code{\link[base:substring]{base::substring()}}, the replacement form
+(\code{substring(text, first, last) <- value}) is not supported.
 }
 \examples{
 str <- paste(
diff --git a/man/format_error.Rd b/man/format_error.Rd
index 2253ab19..e67a95ce 100644
--- a/man/format_error.Rd
+++ b/man/format_error.Rd
@@ -17,6 +17,9 @@ format_message(message, .envir = parent.frame())
 
 \item{.envir}{Environment to evaluate the glue expressions in.}
 }
+\value{
+A character string containing the formatted message.
+}
 \description{
 You can then throw this message with \code{\link[=stop]{stop()}} or \code{rlang::abort()}.
 }
diff --git a/man/ruler.Rd b/man/ruler.Rd
index f8997ca0..a0e8cce8 100644
--- a/man/ruler.Rd
+++ b/man/ruler.Rd
@@ -9,6 +9,10 @@ ruler(width = console_width())
 \arguments{
 \item{width}{Ruler width.}
 }
+\value{
+\code{NULL}, invisibly. Called for its side effect of printing a
+ruler to the screen.
+}
 \description{
 Print the helpful ruler to the screen
 }
diff --git a/man/simple_theme.Rd b/man/simple_theme.Rd
index dc93507d..2ef43865 100644
--- a/man/simple_theme.Rd
+++ b/man/simple_theme.Rd
@@ -12,6 +12,9 @@ background. If \code{"auto"}, then cli will try to detect this.
 Detection usually works in recent RStudio versions, and in iTerm
 on macOS, but not on other platforms.}
 }
+\value{
+A named list that can be used as a cli theme.
+}
 \description{
 To use this theme, you can set it as the \code{cli.theme} option.
 Note that this is in addition to the builtin theme, which is still in
diff --git a/man/spark_bar.Rd b/man/spark_bar.Rd
index 65cc785e..2cac5f5f 100644
--- a/man/spark_bar.Rd
+++ b/man/spark_bar.Rd
@@ -9,6 +9,9 @@ spark_bar(x)
 \arguments{
 \item{x}{A numeric vector between 0 and 1}
 }
+\value{
+A character string of class \code{cli_spark_bar} and \code{cli_spark}.
+}
 \description{
 Rendered using \href{https://en.wikipedia.org/wiki/Block_Elements}{block elements}.
 In most common fixed width fonts these are rendered wider than regular
diff --git a/man/spark_line.Rd b/man/spark_line.Rd
index 1f592fd8..81919eca 100644
--- a/man/spark_line.Rd
+++ b/man/spark_line.Rd
@@ -9,6 +9,9 @@ spark_line(x)
 \arguments{
 \item{x}{A numeric vector between 0 and 1}
 }
+\value{
+A character string of class \code{cli_spark_line} and \code{cli_spark}.
+}
 \description{
 You might want to avoid sparklines on non-UTF-8 systems, because they
 do not look good. You can use \code{\link[=is_utf8_output]{is_utf8_output()}} to test for support
diff --git a/man/test_that_cli.Rd b/man/test_that_cli.Rd
index 37ad4a8c..287ec0f6 100644
--- a/man/test_that_cli.Rd
+++ b/man/test_that_cli.Rd
@@ -31,6 +31,10 @@ vector with possible hyperlink configurations:
 \item \code{"none"}: turn off all hyperlinks.
 }}
 }
+\value{
+The return value of \code{\link[testthat:test_that]{testthat::test_that()}} for the last
+configuration tested (invisibly).
+}
 \description{
 Use this function in your testthat test files, to test cli output.
 It requires testthat edition 3, and works best with snapshot tests.