Before version 8.7, Y2PTF was used for storing and managing Program Temporary Fixes (PTFs). And that for version 8.7+, it is not needed anymore as PTFs are moved to Y2SY. When Y2PTF library is present in CA 2E 8.7 or higher, the administrator could wonder if it can be deleted. This question could be raised when prepare for Ca 2E upgrade.
In CA 2E 8.7 and higher, Y2PTF is not a product library. In other words, the presence of this library suggests that some user objects may be stored in it and it should not be deleted in that case.
Administrator can run
DSPLIB Y2PTF
and check its contents to understand what are stored in this library. The administrator should consult with the development team to gain a better understanding of the library's contents before making a deletion decision. It is recommended to back up this library if the administrator decides to delete it.