Apsel's Dagger is a unique unenchanted dagger.
|“||This dagger was created by Apsel the Scrimshander, a resident of Easthaven. The dagger has a keen edge, and the grip is made of intricately carved knucklehead trout bone.||”|
The only functional difference to a plain dagger is the +1 THAC0 bonus.
Unlike a dagger +1, it has no damage bonus and is considered an unenchanted weapon for the purposes of what it can hit.