[Users] Avpops: source/flags "ru" unknown

[kjcsb]

I am trying to use avpops and getting the following message in the log file:
ERROR:avpops:fixup_db_avp: source/flags "ru" unknown!

The relevant part from openser.cfg is:
avp_db_load("$ru/username", "s:Variable");

However when I look at the pseudo-variables documentation $ru is defined.

Curiously, elsewhere I am using avp_db_load("$from", "s:Variable"); and that 
works even though $from is not defined as a pseudo-variable in the 
documentation. Am I missing something?

OpenSer 1.0.1

Any advice appreciated.

Cameron