@section @code{sigemptyset}
@findex sigemptyset
-POSIX specification: @url{http://www.opengroup.org/susv3xsh/sigemptyset.html}
+POSIX specification: @url{http://www.opengroup.org/onlinepubs/9699919799/functions/sigemptyset.html}
Gnulib module: sigprocmask