only a few decades, ago all entries in medical records were in handwrithing
as opposed to nowadays when only most of them are. Some of the longer ones are dictated but we still use lots of x's.
Dx =diagnosis
Hx =history
Abx =antibiotics.
We even use them in speech. The other day I heard a nurse say "We D/c'd the qHS IV and started oral Abx q4h."