ITS#5942, #5987 - note that when we say "the URI must be the same as

the URI of the provider" we actually mean it. (unlike the rest of the
documentation, where we're just kidding around, of course...)

doc/guide/admin/replication.sdf

@@ -839,7 +839,14 @@ We still have to replicate the actual data, not just the config, so add to the m
 >     objectClass: olcSyncProvConfig
 >     olcOverlay: syncprov
 
-Note: You must have all your servers set to the same time via {{http://www.ntp.org/}}
+Note: All of your servers' clocks must be tightly synchronized using
+e.g. NTP {{http://www.ntp.org/}}, atomic clock, or some other reliable
+time reference.
+
+Note: As stated in {{slapd-config}}(5), URLs specified in {{olcSyncRepl}}
+directives are the URLs of the servers from which to replicate. These
+must exactly match the URLs {{slapd}} listens on ({{-h}} in {{SECT:Command-Line Options}}).
+Otherwise slapd may attempt to replicate from itself, causing a loop.
 
 H3: MirrorMode