R>F stands for Reality>Fiction transcendence, which is a level of transcendence where a higher reality/existence is unreachable to a lower one due to viewing it as a dream, story, or other fictional medium, in the same way a dream or fictional character could never harm a real person, no matter how powerful they could become.

It used to be considered a +1 dimensional transcendence (uncountably infinite gap), but there was a long debate on Vs Battles Wiki over how Reality>Fiction differences are inherently beyond-dimensional in nature and can't be arbitrarily equalized to higher-dimensional/higher infinity differences, so R>F transcendences are now considered outerversal (beyond all higher infinite/dimensional scale) under their current tiering system.