You can also use 12th and 13th returns of GetItemInfo to check for artefact relics, this way you don't need to care about client locale.
Lua Code:
local function isEquip(itemID)
local equipLoc, _, _, classID, subClassID = select(9, GetItemInfo(itemID))
if (classID == 3 and subClassID == 11) or (equipLoc ~= "" and equipLoc ~= "INVTYPE_BAG") then
return true
end
return
end