LLBDTiberio said:One of mine is "ta", both used online and in person, for the first time yesterday I heard a friend utter this horrible substitution for thank you to me
Generally it's internet slang used in real life.
No it's not internet slang at all, in fact it pre-dates the internet by quite some time.. 'Ta' comes from the original Danish word for thanks, 'Tak'. Due to the way we British speak the 'K' was dropped and 'Ta' was used instead.