Ok, it's good to know. I've sent a request today to Harald for an access to the Wiki (according to the instructions on the login page), I would like to update the GsOsmoSdr page, I think it would be very nice if all the options were documented, with device specific information and example too.
Indeed, that page requires some work. A good start is the original block documentation:
http://cgit.osmocom.org/cgit/gr-osmosdr/tree/grc/gen_osmosdr_blocks.py#n103
Best regards,
Dimitri