MarsSeed [1] filed a deletion request for isl16 [2]:

This legacy version from 2016 has its source deleted (404).

But it seems it is not needed specifically by anything in AUR.

So I recommend to delete this if there are no objections.

There are no user votes or comments that would indicate that anyone would protest.

[1] https://aur.archlinux.org/account/MarsSeed/ [2] https://aur.archlinux.org/pkgbase/isl16/