Section 12:13

13. In order to determine what, if any, assignment has been placed on his schedule for the
period following his release, a reserve pilot is required to check and acknowledge his
schedule via DBMS/VRU after completion of the last flight segment of a rotation and
prior to release. At that time, his schedule may show an assignment:
a. of a rotation with a report that is at least 12 hours after his release.
b. to short call duty beginning no earlier than 10 hours after his release. (see
Section 23 S. 9. b. Exception)
c. of a rest period beginning as early as his release time.

23 S 9b exception

9. A short call pilot:
a. will remain on short call for a period that:
1) is designated by Crew Scheduling, and
2) does not exceed:
a) 12 hours in domestic categories, or
b) 24 hours in international categories

FWIW, if you have access to DALnet or Dal.alpa.org you have access to a pdf file of the PWA!