Here it is verbatim.
20-J-3 Short Call Reserve
Converting long
call to short call
20-J-3-a In lieu of a flying assignment, a Long Call
reserve may be converted to a Short Call window that is
up to fifteen (15) hours in duration. Short Call windows
may be aggressively picked up by Long Call reserves in
accordance with paragraph 20-J-4-c below.
20-J-3-b There is no pay credit value for a Short Call
window when the pilot is not used.
(This means that you only get paid for a short call if they assign you a trip)
20-J-4-d There is a limit of seven (7) Short Call
assignments per month (except as provided in Paragraphs
20-J-3-l and 20-J-3-s above); this limit can be exceeded
with pilot concurrence.
20-J-4-e If a reserve has reached four (4) conversions for
the month, the crew desk will bypass him and convert a
pilot who is below him in FIFO if in the same silo.
20-J-4-f RDOs will not be moved to assign a pilot to Short