recentf-string-member

recentf-string-member is a compiled Lisp function in `recentf.el'.

(recentf-string-member ELT LIST)

Return non-nil if ELT is an element of LIST.
The value is actually the tail of LIST whose car is ELT.
ELT must be a string and LIST a list of strings.
Ignore case if `recentf-case-fold-search' is non-nil.