prescriptive

adjective
1
telling people what should be done
دستوری, امرانه, تجویزی
2
telling people how a language should be used, rather than describing how it is used
تجویزی, دستوری
a prescriptive grammar of English
opposite descriptive
3
made legal or acceptable because they have existed for a long time
عرفی, رسمی, مرسوم
prescriptive powers