There is type "Armor Set" in the wow tcg game, which can not be chosen as search criteria.
There is very few armor sets, but maybe it is a good idea to be able to list them as search results.
I realize that you may have reduced the search criteria for the sake of clarity and ease of use of course.

And [wow]Arrowsong[/wow] seems to be reported as a Shaman weapon as well as Hunter. (i made shaman filter and see this in the results)

Thanks for the heads-up. Armor sets are indeed listed as being of type Armor right now. I'll look into it, and maybe change that. Right now I'm waiting for the Wrathgate expansion to see what structural things change with it, and maybe for a comprehensive rules document from Cryptozoic, that would define (or redefine) some of these things. Whatever they define, I'll abide :)

[wow]Arrowsong[/wow] was indeed wrongly linked to the Shaman class as well. It's fixed now.

There was another "hunter only" card in naxx that was reported as shaman too.
Naxx and Scourge cards are entered manually in the database for sure, so mistakes happen.

Checked the card: Envoy of Mortality

Fixed [wow]Envoy of Mortality[/wow] as well.

Thanks! (It's possible that there are more of these mistakes, of course :))