In the old Xwiki rights screen (0.9.840 style), you could type in any text as a permission type (instead of view, edit, programming, etc), this means you could use dynamic permissions instead of group looping to determine different options for certain users.  This means that you do not have to loop groups (or any other object) to restrict the options.

In the new xwiki rights assignment panel there is no obvious possibility to add to the permissions list (they are a scroll list, I would assume they are based on a database entry).

Any chance there is a way I can manually add to this list on my local wiki for the time being?

Brandon Esbach
Software Engineer
M/A-Com Eurotec Operations
LoughMahon Technology Park,
Skehard Road,
Blackrock,
Cork, Ireland
Tel  +353 21 4808305