Provided by: libfontconfig1-dev_2.12.6-0ubuntu2_amd64 

NAME
FcStrSetDel - delete from a string set
SYNOPSIS
#include <fontconfig/fontconfig.h>
FcBool FcStrSetDel (FcStrSet *set, const FcChar8 *s);
DESCRIPTION
Removes s from set, returning FcTrue if s was a member else FcFalse.
Fontconfig 2.12.6 05 April 2018 FcStrSetDel(3)