Here is an example of what I am trying to do, these hostnames are not real; the real ones have no common pattern.

filter f_xyz         { host("*.abca.*") or host(".*abcb.*") or host(".*abcc.*") or host(".*abcd.*") or host(".*abce.*") or host(".*abcf.*") or host(".*abcg.*") or host(".*abch.*"); };

The filter above is for any host containing a hostname with what is contained within the .* and *.; i.e. hostabca01 will be matched by host("*.abca.*")

When I have this filter in my config, syslog fails to restart.

Eyes hurt, obvious mistake?