diff --git a/plugins/bashmarks/README.md b/plugins/bashmarks/README.md
index aec79db..e78c43e 100644
--- a/plugins/bashmarks/README.md
+++ b/plugins/bashmarks/README.md
@@ -1,7 +1,9 @@
 # Bashmarks plugin
 
 The Bashmarks plugin allows you to create and use bookmarks for directories on
-your filesystems.
+your filesystems.  This plugin is derived from the project
+https://github.com/huing/bashmarks but contains improvements.  This plugin is
+licensed under the 3-Clause BSD license.
 
 ## Quickstart
 
@@ -41,6 +43,12 @@ $ bm -l
   the information of bookmarks of directory names. The default path is
   `~/.sdirs`.  The old interface `SDIRS` is now deprecated.
 
+## Configuration
+
+- `BASHMARKS_SDIR`: This variable contains the path to the file that stores the
+  information of bookmarks of directory names. The default path is `~/.sdirs`.
+  The old interface `SDIRS` is now deprecated.
+
 ## Commands
 
 **bm -h** Print short help text