R rotunda

The r rotunda  ꝛ , "rounded r", is a historical calligraphic variant of the minuscule (lowercase) letter Latin r used in full script-like typefaces, especially blackletters.

Unlike other letter variants such as "long s" which originally were orthographically distinctive, r rotunda has always been a calligraphic variant, used when the letter r followed a letter with a rounded stroke towards the right side, such as o, b, p, h (and d in typefaces such as Fraktur where this letter has no vertical stroke, and appears similar to 𝔡). In this way, it is comparable to numerous other special types used for ligatures or conjoined letters in early modern typesetting.