Quote Originally Posted by Oren Grad View Post
Evidently it was discontinued around 1995, as per this discussion list post from 1999:

ILFORD ID 11 Plus was discontinued about 4 years ago because it was found
that Cinnamic acid disulfide appeared to reduce the film speed of some new
technology films.

If it was discontinued it was "FIXED" and reintroduced because it's still available....