Prescriptive (adjective)

1. Describing rules or guidelines that dictate how things should be done or used.
2. Providing guidance on what is proper, correct, or acceptable.
3. Having the power to dictate or enforce rules.

Origin:

From latin praescribere, meaning 'to prescribe'.

Examples:

1. The prescriptive grammar book provided rules for proper English usage.
2. The school's dress code was prescriptive, stating what was acceptable and what was not.
3. The prescriptive approach to ethics dealt with questions of right and wrong conduct.
4. The prescriptive norms of the community dictated how people should behave in social situations.
5. The prescriptive regulations set by the government defined the procedures for starting a business.