-When the buffer is too small, this function does not fail, but instead
-truncates the result and returns 0 on some platforms:
-OSF/1 5.1.
+When the buffer is too small and the value is in range, this function
+does not fail, but instead truncates the result and returns 0 on some
+platforms:
+AIX 6.1, OSF/1 5.1.
+@item
+When the value is not in range or the buffer is too small, this
+function fails to leave a NUL-terminated string in the buffer on some
+platforms:
+glibc 2.13, FreeBSD 8.2, Solaris 10.