Add reference to POSIX.

[pspp] / doc / headers / ctype.texi

diff --git a/doc/headers/ctype.texi b/doc/headers/ctype.texi
index dda21259f3b1f074708d2055700a0564b49554ac..65dc745ce6fb86ce5def5540c3359919a144467c 100644 (file)
--- a/doc/headers/ctype.texi
+++ b/doc/headers/ctype.texi
@@ -1,6 +1,8 @@
 @node ctype.h
 @section @file{ctype.h}
 
+POSIX specification: @url{http://www.opengroup.org/susv3xbd/ctype.h.html}
+
 Gnulib module: ---
 
 Portability problems fixed by Gnulib: