Excuse me, we do not call these jargons.
It's just a more contracted form of English than the one we know already.
Can not > can't
Do not > don't
This can't, don't, 't form itself is not accepted in formal language.
Zis language hs neva bin a part of English. It's just a 'convenient' (really ?) way of typing new generations have unfortunately adopted. Don't even think of writing that in a formal piece.
Everybody does not use the same contracted form, and it has been remarked to vary from country to country, while English is supposed to be a universal language.
If I am so irritated and annoyed when people write (leave whatever) however they wish to, imagine how the examiner would be.
We once had a case in Mauritius, where a student was so addicted to 'texting' that he wrote the whole essay in text form. It was a news... not very well agreed to... by the examiners. Actually, it was
catastrophic.