diff --git a/Documentation/technical/api-submodule-config.txt b/Documentation/technical/api-submodule-config.txt
deleted file mode 100644
index fb06089393..0000000000
--- a/Documentation/technical/api-submodule-config.txt
+++ /dev/null
@@ -1,66 +0,0 @@
-submodule config cache API
-==========================
-
-The submodule config cache API allows to read submodule
-configurations/information from specified revisions. Internally
-information is lazily read into a cache that is used to avoid
-unnecessary parsing of the same .gitmodules files. Lookups can be done by
-submodule path or name.
-
-Usage
------
-
-To initialize the cache with configurations from the worktree the caller
-typically first calls `gitmodules_config()` to read values from the
-worktree .gitmodules and then to overlay the local git config values
-`parse_submodule_config_option()` from the config parsing
-infrastructure.
-
-The caller can look up information about submodules by using the
-`submodule_from_path()` or `submodule_from_name()` functions. They return
-a `struct submodule` which contains the values. The API automatically
-initializes and allocates the needed infrastructure on-demand. If the
-caller does only want to lookup values from revisions the initialization
-can be skipped.
-
-If the internal cache might grow too big or when the caller is done with
-the API, all internally cached values can be freed with submodule_free().
-
-Data Structures
----------------
-
-`struct submodule`::
-
-	This structure is used to return the information about one
-	submodule for a certain revision. It is returned by the lookup
-	functions.
-
-Functions
----------
-
-`void submodule_free(struct repository *r)`::
-
-	Use these to free the internally cached values.
-
-`int parse_submodule_config_option(const char *var, const char *value)`::
-
-	Can be passed to the config parsing infrastructure to parse
-	local (worktree) submodule configurations.
-
-`const struct submodule *submodule_from_path(const unsigned char *treeish_name, const char *path)`::
-
-	Given a tree-ish in the superproject and a path, return the
-	submodule that is bound at the path in the named tree.
-
-`const struct submodule *submodule_from_name(const unsigned char *treeish_name, const char *name)`::
-
-	The same as above but lookup by name.
-
-Whenever a submodule configuration is parsed in `parse_submodule_config_option`
-via e.g. `gitmodules_config()`, it will overwrite the null_sha1 entry.
-So in the normal case, when HEAD:.gitmodules is parsed first and then overlayed
-with the repository configuration, the null_sha1 entry contains the local
-configuration of a submodule (e.g. consolidated values from local git
-configuration and the .gitmodules file in the worktree).
-
-For an example usage see test-submodule-config.c.
diff --git a/submodule-config.h b/submodule-config.h
index 1b4e2da658..42918b55e8 100644
--- a/submodule-config.h
+++ b/submodule-config.h
@@ -7,9 +7,31 @@
 #include "submodule.h"
 #include "strbuf.h"
 
+/**
+ * The submodule config cache API allows to read submodule
+ * configurations/information from specified revisions. Internally
+ * information is lazily read into a cache that is used to avoid
+ * unnecessary parsing of the same .gitmodules files. Lookups can be done by
+ * submodule path or name.
+ *
+ * Usage
+ * -----
+ *
+ * The caller can look up information about submodules by using the
+ * `submodule_from_path()` or `submodule_from_name()` functions. They return
+ * a `struct submodule` which contains the values. The API automatically
+ * initializes and allocates the needed infrastructure on-demand. If the
+ * caller does only want to lookup values from revisions the initialization
+ * can be skipped.
+ *
+ * If the internal cache might grow too big or when the caller is done with
+ * the API, all internally cached values can be freed with submodule_free().
+ *
+ */
+
 /*
  * Submodule entry containing the information about a certain submodule
- * in a certain revision.
+ * in a certain revision. It is returned by the lookup functions.
  */
 struct submodule {
 	const char *path;
@@ -41,13 +63,27 @@ int parse_update_recurse_submodules_arg(const char *opt, const char *arg);
 int parse_push_recurse_submodules_arg(const char *opt, const char *arg);
 void repo_read_gitmodules(struct repository *repo);
 void gitmodules_config_oid(const struct object_id *commit_oid);
+
+/**
+ * Same as submodule_from_path but lookup by name.
+ */
 const struct submodule *submodule_from_name(struct repository *r,
 					    const struct object_id *commit_or_tree,
 					    const char *name);
+
+/**
+ * Given a tree-ish in the superproject and a path, return the submodule that
+ * is bound at the path in the named tree.
+ */
 const struct submodule *submodule_from_path(struct repository *r,
 					    const struct object_id *commit_or_tree,
 					    const char *path);
+
+/**
+ * Use these to free the internally cached values.
+ */
 void submodule_free(struct repository *r);
+
 int print_config_from_gitmodules(struct repository *repo, const char *key);
 int config_set_in_gitmodules_file_gently(const char *key, const char *value);