diff --git a/mysql/README.md b/mysql/README.md
index d94116477308..84cdbbc5cf12 100644
--- a/mysql/README.md
+++ b/mysql/README.md
@@ -74,12 +74,14 @@ This variable is mandatory and specifies the password that will be set for the M
 
 ### `MYSQL_DATABASE`
 
-This variable is optional and allows you to specify the name of a database to be created on image startup. If a user/password was supplied (see below) then that user will be granted superuser access ([corresponding to `GRANT ALL`](http://dev.mysql.com/doc/en/adding-users.html)) to this database.
+This variable is optional and allows you to specify the name of a database to be created on image startup. If a user/password was supplied (see below) then that user will be granted superuser access ([corresponding to `GRANT ALL`](http://dev.mysql.com/doc/en/adding-users.html)) to this database. To create more than one database use MYSQL_DATABASE1, MYSQL_DATABASE2 and so on.
 
 ### `MYSQL_USER`, `MYSQL_PASSWORD`
 
 These variables are optional, used in conjunction to create a new user and to set that user's password. This user will be granted superuser permissions (see above) for the database specified by the `MYSQL_DATABASE` variable. Both variables are required for a user to be created.
 
+If you create more than one database (see above) the user supplied as MYSQL_USER will be granted access to all databases. If you need separate users with access to only one database specify them as eg. MYSQL_USER1 and MYSQL_PASSWORD1 where the number matches the appropriate database.
+
 Do note that there is no need to use this mechanism to create the root superuser, that user gets created by default with the password specified by the `MYSQL_ROOT_PASSWORD` variable.
 
 ### `MYSQL_ALLOW_EMPTY_PASSWORD`