2011/04/13 : List of possible cookie settings with associated behaviours.

PSV="preserve", PFX="prefix", INS="insert", REW="rewrite", IND="indirect"
0 = option not set
1 = option is set
* = option doesn't matter

PSV PFX INS REW IND   Behaviour
 0   0   0   0   0    passive mode
 0   0   0   0   1    passive + indirect : remove response if not needed
 0   0   0   1   0    always rewrite response
 0   0   1   0   0    always insert or replace response
 0   0   1   0   1    insert + indirect : remove req and also resp if not needed
 *   *   1   1   *    [ forbidden ]
 0   1   0   0   0    prefix
 0   1   0   0   1    !! prefix on request, remove reponse cookie if not needed
 *   1   *   1   *    [ forbidden ]
 *   1   1   *   *    [ forbidden ]
 *   *   *   1   1    [ forbidden ]
 1   *   0   *   0    [ forbidden ]
 1   0   0   0   1    passive mode (alternate form)
 1   0   1   0   0    insert only, and preserve server response cookie if any
 1   0   1   0   1    conditional insert only for new requests
 1   1   0   0   1    prefix on requests only (passive prefix)