Each of the decade-long books has a set of lists which cover artists not covered in the book. In particular, "Subjects for Further Research" (SFFR) refers to artists probably worth further consideration than was possible at the time of writing. "Distinctions Not Cost-Effective" is pretty much the opposite, although those artists get more consideration than the ones listed in "Meltdown."
The book sections for SFFR are:
The other list sections tend to follow in the books.
These entries are also provided in the per-artist Consumer Guide pages. The artists with further notes are: