I was wondering, people are saying that one handed perks and enchantments for increased damage do not effect daggers? Is this true? :brokencomputer:

I believe it is, but this is offset by the huge backstab bonuses daggers have. If you think about it, would you really attack a guy face to face with a dagger if he has a sword? And, backstabbing would be easier with a dagger as compared to a sword. So yeah, I think it works out as is and makes sense.

Daggers don't benefit from the One-Handed perks (except for the Dual Wield perks but that's an indirect result), but does calculate its damage on the One-Handed skill.

As for the enchantments, a One-Handed damage enchantment should effect it since it enhances the base skill, however the dagger's base damage is pretty small so it would take a rather strong enchantment to see any obvious benefits.

Daggers benefit from Armsman. I can personally confirm that.