# Name for diagonals of a matrix

I am looking for the terms to use for particular types of diagonals in two dimensional matrices. I have heard the longest diagonal, from top-left element and in the direction down-right often called the "leading diagonal".

-What about the 'other' diagonal, from the top right going down-left? Does it have a common name?

-Any general name to use for any diagonal going top-left to bottom-right direction, not necessarily just the longest one(s)? I am searching for a term to distinguish between these types of diagonals and the ones in the 'other' direction. Preferably the term should not be restricted to square matrices.

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$\diagdown$ Major, Principal, Primary, Main; diagonal $\diagdown$

$\diagup$ Minor, Counter, Secondary, Anti-; diagonal $\diagup$

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