In the Forsaken starting area and within Tirisfal Glades), many of the common (white) quality items are flagged by ATT as "not collected". It's my understanding that common quality items cannot be transmogged and therefore have no value to a collection.

A few of the items (such as simmer's bracers and simmer's dirk) do share appearances with items that can be learned, but others (ie; Flax Vest) cannot.

None of the common-quality items have the blue "You haven't collected this appearance" message.

It should be in the next update.

Yeah, we are working on it for a while now.

Thanks. Sorry, I looked a bit but didn't see this as a known issue.

Feel free to close this out as a duplicate.

This is fixed in commit 0556168