Melee attacks can be blocked, if the enemy is capable of such. Ranged attacks can be dodged, but not parried or blocked.
If you can't accept this from an mmo thread, you should check with Zeherah or perhaps Elitist Jerks, or you could use your own brain and try things out on a target dummy - see if you get parried.
You'll find the answer is NEVER.
You'll NEVER see a block, either, unless possibly you unequip your ranged and attempt to melee.
Lack of parry isn't lack of block. Hunter shots can be blocked and you are proven wrong in the post above me. My question to you is, how can you be so ignorant?