Source : WordNet®

guideline
     n 1: a light line that is used in lettering to help align the
          letters
     2: a detailed plan or explanation to guide you in setting
        standards or determining a course of action; "the
        president said he had a road map for normalizing relations
        with Vietnam" [syn: {road map}]
     3: a rule or principle that provides guidance to appropriate
        behavior [syn: {guidepost}, {rule of thumb}]