Variations of RP

Accents of English 2: The British Isles by J. C. Wells (1982)

Gimson’s varieties of RP (1980)
Conservative RP is ‘used by the older generation and, traditionally, by certain professions or social groups’.
General RP is ’most commonly in used and typified by the pronunciation adopted by the BBC’.
Advanced RP is ‘mainly used by young people of exclusive social groups-mostly of the upper classes, but also, for prestige value, in certain professional circles’.

Wells’s varieties of RP
RP consists of mainstream RP (U-RP and adoptive RP) and Near-RP
Upper-crust RP (U-RP) is accent for upper class people
Adoptive RP is ‘variety of RP spoken by adults who did not speak RP as children’. The speaker of adoptive RP tend to retain their native accent of English and the both native and adoptive accents often appear in the case of informal or formal situation. It is not easy for them to control elision, assimilation, smoothing, /r/,/hw/, /t/. /i:/, /u:/ and diphthongs.
Near-RP is accent which doesn’t apply to the definition of RP but includes regional one slightly.