Complex sentence: To distinguish "authentication" from the closely related "authorization", the short-hand notations A1 (authentication), A2 (authorization) as well as AuthN/AuthZ (AuthR) or Au/Az are used in some communities.
Split into simpler sentences: To distinguish "authentication" from the closely related term "authorization," the short-hand notations A1 (authentication) and A2 (authorization) are occasionally used. The terms AuthN/AuthZ (AuthR) or Au/Az are also used to make this distinction in some communities.