diff --git a/xep-0313.xml b/xep-0313.xml
index d78779c6..24f85884 100644
--- a/xep-0313.xml
+++ b/xep-0313.xml
@@ -29,6 +29,14 @@
&mwild;
&ksmith;
+ Add implementation note about before/after and before-id/after-id If the client has already seen some messages, it may choose to restrict its query to
before and/or after messages it already knows about. This may be done through the 'before-id'
- and 'after-id' fields.
+ Queries in the 'urn:xmpp:mam:2' namespace can be limited using the RSM + 'before' and 'after' parameters. + Normally these are opaque identifiers that are not known until the results + of the first query are returned at which point they can be used to fetch + subsequent pages. + However, MAM specifically defines them as being equal to the archive ID, + meaning that an acceptable value can be known and used in the initial query. + This makes them equivalent to 'before-id' and 'after-id' defined in the + 'urn:xmpp:mam:2#extended' namespace except for the following differences: +
+This specification defines the following XML namespace: