Here are some abbreviations used by stamp collectors to describe stamps for sale:

MNH mint never hinged. The stamp has original gum.

MH mint hinged

MHH mint heavy hinge

MHR mint hinge remnant not removed

MDG mint disturbed gum

MNGAI mint no gum as issued

U used

CTO canceled to order

SON cancel is complete on the front of the stamp

PC pen cancel obvious

If there are faults in the stamp, these abbreviations are typical used:

OC obliteration cancel

PP pulled perforations

SC scuff on face

F filler

ST stained

T tear

TN toning

TH thin

CR crease