Read from the World of Warcraft client build files (JournalEncounterItem, JournalEncounterCreature, Achievement) and the Blizzard Game Data quest API.
How Cryptbound Headpiece Compares
Who It Suits
Mail is the armor type Evoker, Hunter and Shaman wear. With Agility or Intellect, Cryptbound Headpiece suits Beast Mastery, Marksmanship and Survival Hunter; Elemental, Enhancement and Restoration Shaman; Devastation, Preservation and Augmentation Evoker.
Transmog Sets
Cryptbound Headpiece is part of the transmog set Algari Chainmail (Hunter, Shaman and Evoker only). The other 16 pieces:
Blizzard numbers items as they are created, so the named items next to ID 221156 (221151 to 221161) were usually added in the same batch as Cryptbound Headpiece: the same quest line, zone, vendor or reward set.