Typically it is used on a desired member of the opposite sex, that is normally not desired during sober hours. This lame attempt to arrange a booty call results from the cowardice of the drunk texter, who fears actually making the drunk dial.
There are many ways to know that someone is drunk texting you, such as the culprit posting 'Going out for a drink or two' as his or her facebook status a little earlier. Or by your friend bringing up old stories from their past childhood, or even when they begin to put 'lol' or 'hahah' a lot more.
Andrea: Oh cool, a new message from Janelle. (reads to herself) " Hey remember thaert time where you knocefrfked your little sisdter out with a recorsd?"
- Andrea thinks to herself : Who gave her the George Dickle again, she has got to be drunk texting. -