Read from the World of Warcraft client build files.
Where Dominant Gladiator's Tabard Fits
Items Numbered Next to Dominant Gladiator's Tabard
Blizzard numbers items as they are created, so the named items next to ID 149447 (149442 to 149452) were usually added in the same batch as Dominant Gladiator's Tabard: the same quest line, zone, vendor or reward set.