ɹ

Symbol

 * 1)  an alveolar approximant.
 * -coloring of a vowel, or a weak, fleeting or epenthetic.

Usage notes
⟨˞|V˞⟩ (vowel with hook diacritic) is now standard IPA for a generic rhotic vowel. ⟨Vʴ⟩ remains in use in English dialectology to indicate specific rhotic coloring in close transcription, e.g. alveolar as opposed to post-alveolar, labiodental  or uvular. The obsolete IPA variant ⟨Vʳ⟩ is not used in such situations (at least for English) because it would indicate that the vowel was trilled.