Read from the World of Warcraft client build files.
How Forged Gladiator's Silk Raiment Compares
Who It Suits
Cloth is the armor type Mage, Priest and Warlock wear. With Intellect, Forged Gladiator's Silk Raiment suits Discipline, Holy and Shadow Priest; Arcane, Fire and Frost Mage; Affliction, Demonology and Destruction Warlock.
Transmog Sets
Forged Gladiator's Silk Raiment is part of the transmog set Forged Gladiator's Silk Armor (Warlock only), which the Appearances collection lists in 3 versions. The other 16 pieces:
Items Numbered Next to Forged Gladiator's Silk Raiment
Blizzard numbers items as they are created, so the named items next to ID 218498 (218493 to 218503) were usually added in the same batch as Forged Gladiator's Silk Raiment: the same quest line, zone, vendor or reward set.