prescriptive rule
preskriptiivne reegel
olemus
Wiktionary:
prescriptive, adj:
of or pertaining to prescribing or enjoining, especially an action or behavior based on a norm or standard
vt ka
https://www.quora.com/What-is-difference-between-prescriptive-and-descriptive
https://www.edwardtesol.com/uploads/2/6/5/8/26581579/ppt_prescriptive_vs_descriptive.pdf
https://en.wikipedia.org/wiki/Linguistic_prescription