diff --git a/Documentation/technical/api-directory-listing.txt b/Documentation/technical/api-directory-listing.txt
deleted file mode 100644
index 76b6e4f71b..0000000000
--- a/Documentation/technical/api-directory-listing.txt
+++ /dev/null
@@ -1,130 +0,0 @@
-directory listing API
-=====================
-
-The directory listing API is used to enumerate paths in the work tree,
-optionally taking `.git/info/exclude` and `.gitignore` files per
-directory into account.
-
-Data structure
---------------
-
-`struct dir_struct` structure is used to pass directory traversal
-options to the library and to record the paths discovered.  A single
-`struct dir_struct` is used regardless of whether or not the traversal
-recursively descends into subdirectories.
-
-The notable options are:
-
-`exclude_per_dir`::
-
-	The name of the file to be read in each directory for excluded
-	files (typically `.gitignore`).
-
-`flags`::
-
-	A bit-field of options:
-
-`DIR_SHOW_IGNORED`:::
-
-	Return just ignored files in `entries[]`, not untracked
-	files. This flag is mutually exclusive with
-	`DIR_SHOW_IGNORED_TOO`.
-
-`DIR_SHOW_IGNORED_TOO`:::
-
-	Similar to `DIR_SHOW_IGNORED`, but return ignored files in
-	`ignored[]` in addition to untracked files in
-	`entries[]`. This flag is mutually exclusive with
-	`DIR_SHOW_IGNORED`.
-
-`DIR_KEEP_UNTRACKED_CONTENTS`:::
-
-	Only has meaning if `DIR_SHOW_IGNORED_TOO` is also set; if this is set, the
-	untracked contents of untracked directories are also returned in
-	`entries[]`.
-
-`DIR_SHOW_IGNORED_TOO_MODE_MATCHING`:::
-
-	Only has meaning if `DIR_SHOW_IGNORED_TOO` is also set; if
-	this is set, returns ignored files and directories that match
-	an exclude pattern. If a directory matches an exclude pattern,
-	then the directory is returned and the contained paths are
-	not. A directory that does not match an exclude pattern will
-	not be returned even if all of its contents are ignored. In
-	this case, the contents are returned as individual entries.
-+
-If this is set, files and directories that explicitly match an ignore
-pattern are reported. Implicitly ignored directories (directories that
-do not match an ignore pattern, but whose contents are all ignored)
-are not reported, instead all of the contents are reported.
-
-`DIR_COLLECT_IGNORED`:::
-
-	Special mode for git-add. Return ignored files in `ignored[]` and
-	untracked files in `entries[]`. Only returns ignored files that match
-	pathspec exactly (no wildcards). Does not recurse into ignored
-	directories.
-
-`DIR_SHOW_OTHER_DIRECTORIES`:::
-
-	Include a directory that is not tracked.
-
-`DIR_HIDE_EMPTY_DIRECTORIES`:::
-
-	Do not include a directory that is not tracked and is empty.
-
-`DIR_NO_GITLINKS`:::
-
-	If set, recurse into a directory that looks like a Git
-	directory.  Otherwise it is shown as a directory.
-
-The result of the enumeration is left in these fields:
-
-`entries[]`::
-
-	An array of `struct dir_entry`, each element of which describes
-	a path.
-
-`nr`::
-
-	The number of members in `entries[]` array.
-
-`alloc`::
-
-	Internal use; keeps track of allocation of `entries[]` array.
-
-`ignored[]`::
-
-	An array of `struct dir_entry`, used for ignored paths with the
-	`DIR_SHOW_IGNORED_TOO` and `DIR_COLLECT_IGNORED` flags.
-
-`ignored_nr`::
-
-	The number of members in `ignored[]` array.
-
-Calling sequence
-----------------
-
-Note: index may be looked at for .gitignore files that are CE_SKIP_WORKTREE
-marked. If you to exclude files, make sure you have loaded index first.
-
-* Prepare `struct dir_struct dir` and clear it with `memset(&dir, 0,
-  sizeof(dir))`.
-
-* To add single exclude pattern, call `add_pattern_list()` and then
-  `add_pattern()`.
-
-* To add patterns from a file (e.g. `.git/info/exclude`), call
-  `add_patterns_from_file()` , and/or set `dir.exclude_per_dir`.  A
-  short-hand function `setup_standard_excludes()` can be used to set
-  up the standard set of exclude settings.
-
-* Set options described in the Data Structure section above.
-
-* Call `read_directory()`.
-
-* Use `dir.entries[]`.
-
-* Call `clear_directory()` when none of the contained elements are no longer in use.
-
-(JC)
diff --git a/dir.h b/dir.h
index 2fbdef014f..1b41d29c07 100644
--- a/dir.h
+++ b/dir.h
@@ -1,11 +1,43 @@
 #ifndef DIR_H
 #define DIR_H
 
-/* See Documentation/technical/api-directory-listing.txt */
-
 #include "cache.h"
 #include "strbuf.h"
 
+/**
+ * The directory listing API is used to enumerate paths in the work tree,
+ * optionally taking `.git/info/exclude` and `.gitignore` files per directory
+ * into account.
+ */
+
+/**
+ * Calling sequence
+ * ----------------
+ *
+ * Note: index may be looked at for .gitignore files that are CE_SKIP_WORKTREE
+ * marked. If you to exclude files, make sure you have loaded index first.
+ *
+ * - Prepare `struct dir_struct dir` and clear it with `memset(&dir, 0,
+ * sizeof(dir))`.
+ *
+ * - To add single exclude pattern, call `add_pattern_list()` and then
+ *   `add_pattern()`.
+ *
+ * - To add patterns from a file (e.g. `.git/info/exclude`), call
+ *   `add_patterns_from_file()` , and/or set `dir.exclude_per_dir`.  A
+ *   short-hand function `setup_standard_excludes()` can be used to set
+ *   up the standard set of exclude settings.
+ *
+ * - Set options described in the Data Structure section above.
+ *
+ * - Call `read_directory()`.
+ *
+ * - Use `dir.entries[]`.
+ *
+ * - Call `clear_directory()` when none of the contained elements are no longer in use.
+ *
+ */
+
 struct dir_entry {
 	unsigned int len;
 	char name[FLEX_ARRAY]; /* more */
@@ -144,25 +176,101 @@ struct untracked_cache {
 	unsigned int use_fsmonitor : 1;
 };
 
+/**
+ * pass directory traversal options to the library and to record the paths
+ * discovered. A single `struct dir_struct` is used regardless of whether or
+ * not the traversal recursively descends into subdirectories.
+ */
 struct dir_struct {
-	int nr, alloc;
-	int ignored_nr, ignored_alloc;
+
+    /* The number of members in `entries[]` array. */
+    int nr;
+
+    /* Internal use; keeps track of allocation of `entries[]` array.*/
+    int alloc;
+
+    /* The number of members in `ignored[]` array. */
+	int ignored_nr;
+
+	int ignored_alloc;
+
+	/* bit-field of options */
 	enum {
+
+	    /**
+	     * Return just ignored files in `entries[]`, not untracked files.
+	     * This flag is mutually exclusive with `DIR_SHOW_IGNORED_TOO`.
+	     */
 		DIR_SHOW_IGNORED = 1<<0,
+
+		/* Include a directory that is not tracked. */
 		DIR_SHOW_OTHER_DIRECTORIES = 1<<1,
+
+		/* Do not include a directory that is not tracked and is empty. */
 		DIR_HIDE_EMPTY_DIRECTORIES = 1<<2,
+
+		/**
+		 * If set, recurse into a directory that looks like a Git directory.
+		 * Otherwise it is shown as a directory.
+		 */
 		DIR_NO_GITLINKS = 1<<3,
+
+		/**
+		 * Special mode for git-add. Return ignored files in `ignored[]` and
+	     * untracked files in `entries[]`. Only returns ignored files that match
+	     * pathspec exactly (no wildcards). Does not recurse into ignored
+	     * directories.
+		 */
 		DIR_COLLECT_IGNORED = 1<<4,
+
+		/**
+		 * Similar to `DIR_SHOW_IGNORED`, but return ignored files in
+		 * `ignored[]` in addition to untracked files in `entries[]`.
+		 * This flag is mutually exclusive with `DIR_SHOW_IGNORED`.
+		 */
 		DIR_SHOW_IGNORED_TOO = 1<<5,
+
 		DIR_COLLECT_KILLED_ONLY = 1<<6,
+
+        /**
+         * Only has meaning if `DIR_SHOW_IGNORED_TOO` is also set; if this is
+         * set, the untracked contents of untracked directories are also
+         * returned in `entries[]`.
+         */
 		DIR_KEEP_UNTRACKED_CONTENTS = 1<<7,
+
+		/**
+		 * Only has meaning if `DIR_SHOW_IGNORED_TOO` is also set; if this is
+		 * set, returns ignored files and directories that match an exclude
+		 * pattern. If a directory matches an exclude pattern, then the
+		 * directory is returned and the contained paths are not. A directory
+		 * that does not match an exclude pattern will not be returned even if
+		 * all of its contents are ignored. In this case, the contents are
+		 * returned as individual entries.
+		 *
+		 * If this is set, files and directories that explicitly match an ignore
+         * pattern are reported. Implicitly ignored directories (directories that
+         * do not match an ignore pattern, but whose contents are all ignored)
+         * are not reported, instead all of the contents are reported.
+		 */
 		DIR_SHOW_IGNORED_TOO_MODE_MATCHING = 1<<8,
+
 		DIR_SKIP_NESTED_GIT = 1<<9
 	} flags;
+
+	/* An array of `struct dir_entry`, each element of which describes a path. */
 	struct dir_entry **entries;
+
+	/**
+	 * used for ignored paths with the `DIR_SHOW_IGNORED_TOO` and
+	 * `DIR_COLLECT_IGNORED` flags.
+	 */
 	struct dir_entry **ignored;
 
-	/* Exclude info */
+	/**
+	 * The name of the file to be read in each directory for excluded files
+	 * (typically `.gitignore`).
+	 */
 	const char *exclude_per_dir;
 
 	/*
