Authorities
Prescription usually presupposes an authority whose judgment may be followed by other members of a speech community. Such an authority may be a prominent writer or educator such as Henry Fowler, whose English Usage defined the standard for British English for much of the 20th century. The Duden grammar has a similar status for German. Though dictionary makers usually see their work as purely descriptive, they are widely used as prescriptive authorities by the community at large. Popular books such as Lynne Truss's Eats, Shoots & Leaves, which argues for stricter adherence to prescriptive punctuation rules, have phases of fashionability and are authoritative to the degree that they attract a de facto following.

However, in some language communities, linguistic prescription can be regulated formally. The Académie française (French Academy) in Paris is an example of a widely respected national body whose recommendations, though not legally enforceable, carry great authority. In Germany and the Netherlands, recent spelling reforms were devised by teams of linguists commissioned by government, and were then implemented by statute. See for example German spelling reform of 1996. The Russian language was heavily prescribed during the Soviet period, deviations from the norm being purged by the Union of Soviet Writers.

Other kinds of authorities come into play in specific settings, such as publishers laying down a house style which, for example, may either prescribe or proscribe a serial comma.