+@item
+This function is missing on some platforms:
+glibc 2.3.6, MacOS X 10.3, FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, AIX
+5.1, HP-UX 11, IRIX 6.5, OSF/1 5.1, Solaris 10, Cygwin 1.5.x, mingw,
+Interix 3.5, BeOS.
+However, the replacement function may end up truncating timestamps to
+less resolution than supported by the file system.
+@item
+This function returns a bogus value instead of failing with
+@code{ENOSYS} on some platforms:
+Linux kernel 2.6.21.
+@item
+When using @code{UTIME_OMIT} or @code{UTIME_NOW}, some systems require
+the @code{tv_sec} argument to be 0, and don't necessarily handle all
+file permissions in the manner required by POSIX:
+Linux kernel 2.6.25.
+@item
+When using @code{UTIME_OMIT} for the modification time, but specifying
+an access time, some systems fail to update the change time:
+Linux kernel 2.6.32.