sid.mli: add short module blurb

1 files changed, 9 insertions, 0 deletions

diff --git a/sid.mli b/sid.mli
index 9730d14..e2c94df 100644
--- a/sid.mli
+++ b/sid.mli
@@ -1,5 +1,14 @@
 (* SPDX-License-Identifier: LGPL-3.0-only WITH OCaml-LGPL-linking-exception *)
 
+(** Security identifiers.
+
+    {e Sid} implements the “Security Identifier” data type commonly used
+    on the Microsoft Windows platform. When processing input, it tries to
+    adhere as closely to the specification as possible.
+
+    @see <https://msdn.microsoft.com/en-us/library/cc230371.aspx> the relevant
+    section in the {e [MS-DTYP]} compilation of types. *)
+
 type t
 type sub_auths = Stdint.Uint32.t array