r is recte 'correctly'; f is falshe 'falsely'. Usually on a birth record it says child's given name, father's surname r mother's surname or child's name, mother's surname f father's surname. In these patterns mother's surname is recte and father's surname is falshe, as the government considered the child illegitimate.

Sally Bruckheimer
Princeton, NJ

"This is the area where some birth records will say child's name surname = mother's maiden name r father's surname."