A guideline is a statement by which to determine a course of action.
It aims to streamline particular processes according to a set routine or sound practice.
[1] They may be issued by and used by any organization (governmental or private) to make the actions of its employees or divisions more predictable, and presumably of higher quality.
A guideline is similar to a rule, but are legally less binding as justified deviations are possible.
[2] Examples of guidelines are: This standards- or measurement-related article is a stub.