Section 28 clearly states what company cannot schedule you for after a fatigue call. It says no flight duty or rental car, implying other types of travel, but limited to specific circumstances. 28.5(F)(1)(b) talks about reducing the 14 hr rest period when fatigue is called the second to last assigned duty day in order to avaid "intentional" after midnights. Nowhere does that section address "other" duty, such as Jepps revisions or other paperwork, etc. Since it is not specifically addressed, one could argue anything goes. However, I believe if the CBA does not specifically allow them to, they can't just make stuff up. RAJ says they were kept on duty for another 5 hours, but doesn't specify what type of duty. If there was questionable assigment involved, I would challenge that via the grievance process, whatever the "rep" said.