Based on rules.

A surname.

plural of Rule

(informal) Australian rules football.

(Internet) A type of directive in CSS (Cascading Style Sheets) that is prefixed with the at sign @.

plural of at-rule

(programming) A rule by which compilers are allowed to apply any optimizing transformation to a program provided that it makes no change to the observable behavior of the program.

(music) A rule that modifies a well-formed structure (in limited ways). / (grammar) A rule that takes an input and changes it in some restricted way to result in a surface structure.

Being a notebook with 10½" × 8" paper size with thirty-two evenly spaced lines with enough space to write reasonably neatly.

(slang, derogatory) Someone who attempts to take advantage of a given set of rules, usually by using an overly-literal interpretation that is contrary to their intent, or by selectively choosing which rules take precedence in a given situation.