signature tag

Dear Sir./Miss.:
        I suggest add a tag to html, then we can add a signature to an HTML file.
<sig name="adez" email="adez@21cn.com"  method=pgp >
<!--
-----BEGIN PGP SIGNATURE-----
Version: 2.6.2i

iQCVAwUBMcg5LwQmfXmOCknRAQHpZQP/Qe3oQd0CWTSVklvaDWp5RBx1M5kMUONc
XlQkSRXSFSEwJoQznq7O0krat9fkBzX6A/Qtm5htNeH3WFB7DWRbLneIvtitpqv+
cLyJgGGR04k3J13oRGy2x1yvVEd/L4JpuNLDFc6Jrkx/yuLnQxu8CUp0aeJxi3RO
VHD31+7QYz8=
=QhzE
-----END PGP SIGNATURE-----
-->
</sig>

the digest of the message is caculate from the begin of the file to the last non-white pace char.
and so an HTML can be signed by several peoples.

        Best Regards
            adez