A lot of people asked me how I got my clan tag and emblem on the guns I use well this is how. In Black ops 2 you can now prestige your weapon when you have reached level max(16).
Its done by going onto create class and hitting (Y). Levels and attachments reset but camos stay and you unlock calling cards and more stuff.

Here is a good video showing that(Not mine).


Just in case no one new and trust me a lot of people did not.