meaning "dont fart" while chating online... but if ur chating online then ur most likely not close to that person so it wound not matter if they would fart or not becuse you wound not be able to smell/hear it....
"Il be over in 20 seconds... o ya and DF befor I get there"
"While ur taking care of my dog, make sure u df in his face. He realy dosent like that."
Jo:Hey I said df.
Bob:Hey my code name is not dumb fuck any more.
Jo: No Mean df as in "dont fart". Dammit you really need to go to urbandictionary.com more often. Ur so old school.