Document ml datafeed Id limitations
@@ -24,6 +24,8 @@ You must create a job before you create a {dfeed}. You can associate only one
`feed_id` (required)::
(string) A numerical character string that uniquely identifies the {dfeed}.
+ This identifier can contain lowercase alphanumeric characters (a-z and 0-9),
+ hyphens, and underscores. It must start and end with alphanumeric characters.
==== Request Body
