Multiple caching solutions for anonymous and logged in users with SSI on

[Antonio P.P. Almeida]

> Bird brain me :-)
>
> What does this mean?
>
> ~SESS[[:alnum:]]+=(?<session_id>[[:graph:]]+) $session_id;

It means to grab the sub-token on the right-hand side of the session token.
Using POSIX character classes for the regex:

https://en.wikipedia.org/wiki/Regular_expression#POSIX_character_classes

> Also 'if' is evil inside a location. Right ?

Not really. Here it's a mere return. From the famous IfIsEvil wiki page:

     The only 100% safe things which may be done inside
     if in location context are:

           return ...;
           rewrite ... last;
--appa