A general term meaning "written down in the way most commonly accepted"
It depends on the subject:
• For numbers: in Britain it means "Scientific Notation", in other countries it means "Expanded Form" (such as 125 = 100+20+5)
• For a line it means the form: Ax + By = C
• For equations it means the form: (some expression) = 0
• For a quadratic equation it means the form: ax2 + bx + c = 0
And there are more.
