If there is a space where the name should be, then it was crafted by someone, but that person either left the server or they haven't been on in a while. I believe this happens a lot after maintenance, as I have noticed it seems to not register your name on crafter tags afterwards until you log in again.

If there is no space for a crafter name on the item, it was not crafted and was gotten by some other means. A lot of stuff can be bought through vendors that people like to sell at inflated prices in large quantities on the mb(like steel ingots, vitriol, etc), but if it's an HQ crafted item you're seeing massive quantities of with no place for a crafter name...something's fishy.