Yeah, I noticed that hyc had patched it differently. There is definitely a steep learning curve when it comes to helping out with anything. I see hyc's patch committed in the latest RE24. I have tested it with HEAD and the error message seems to be gone. I can't seem to get olcAuthIDRewrite to work -- but that's probably not an ITS problem. =)

Probably, yes. authzid-rewrite is used much like authz-regexp, only with a slightly different syntax. Actually, when rewriting is available, authz-regexp is handled by authzid-rewrite, using a subset of its syntax (and thus of its semantics). So its use applies when authz-regexp is appropriate. See slapd.conf(5) for usage of authz-regexp.

p.