Known communities for AS174?

[David Hubbard]

Hello, I'm looking for a way to do path prepending
for my prefix as it leaves AS174 (Cogent), one of my
upstreams.  The following:

http://www.radb.net/cgi-bin/radb/whois.cgi?obj=AS174

suggests that at least as recently as last May they
might have accepted:

  3. Communities controlling Cogents AS path prepending
     for customer routes on egress:

     community   effect
     174:3000   do not announce
     174:3001   prepend 174 1 time
     174:3002   prepend 174 2 times
     174:3003   prepend 174 3 times

But I've tried setting each of those and it doesn't
seem to have any effect.  Anyone know if that info is
out of date or maybe has something else to try?

Thanks,

David