Read from the World of Warcraft client build files (JournalEncounterItem, JournalEncounterCreature, Achievement) and the Blizzard Game Data quest API.
How Hallowed Crown Compares
Who It Suits
Cloth is the armor type Mage, Priest and Warlock wear. With Intellect, Hallowed Crown suits Discipline, Holy and Shadow Priest; Arcane, Fire and Frost Mage; Affliction, Demonology and Destruction Warlock.
Transmog Sets
Hallowed Crown is part of the transmog set Hallowed Raiment (Priest, Mage and Warlock only). The other 12 pieces:
Built from the World of Warcraft client build files and recorded Auction House snapshots.
Where Hallowed Crown Fits
Other Items Named Hallowed Crown
1 other item in the current build is also called Hallowed Crown. Same-name entries are usually a different rank, faction, quest stage or reward track of the same object.
Blizzard numbers items as they are created, so the named items next to ID 127169 (127164 to 127174) were usually added in the same batch as Hallowed Crown: the same quest line, zone, vendor or reward set.