guideline

/G AY1 D L AY0 N/
noun
  1. 1

    A non-specific rule or principle that provides direction to action or behaviour.

    โ€œHe considered the Ten Commandments more a guideline than a requirement.โ€

  2. 2

    A plan or explanation to guide one in setting standards or determining a course of action.

  3. 3

    A light line, used in lettering, to help align the text.

Source: https://en.wiktionary.org/wiki/guideline