-FreeBSD 5.2.1, NetBSD 3.0, OpenBSD 3.8, AIX 5.1, HP-UX 11, Solaris 9, Interix 3.5.
+FreeBSD 5.2.1, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, MSVC 9, Interix 3.5.
+@item
+This function is not declared (without @code{-D_GNU_SOURCE}) on some platforms:
+glibc 2.8.
+@end itemize
+
+Portability problems fixed by Gnulib module @code{truncf-ieee}:
+@itemize
+@item
+This function returns a positive zero for a minus zero argument
+on some platforms:
+OSF/1 5.1.