lucy24 - 11:49 am on Feb 28, 2013 (gmt 0)
I don't think you ever need quotation marks in mod_rewrite. You sometimes need them in mod_setenvif-- which is where I've got my equivalent rule-- if your text block contains a literal space. (Hm, come to think of it, could you escape the space instead? That's what you'd do in a RewriteRule.)
The mod_authz version works in conjunction with mod_setenvif. First you list your unwanted UAs:
BrowserMatch Clipish keep_out
BrowserMatch Covario keep_out
BrowserMatch Slurp keep_out
And then when you get to your Deny from directives-- the same place you list all the unwanted IP ranges-- you throw in a sweeping
Deny from env=keep_out
It was not unusual for a decade ago, in fact it was the norm.
Were User Agent strings differently arranged back then, or was it simply the norm for rules not to work? :) It can't possibly be a change in Regular Expressions; they're almost as carved-in-stone as the Unicode consortium.