How to write HTML posts on that forum.

[bronek]

[kenorb]

http://sites.google.com/site/tomihasa/google-groups-faq#htmlinmessages

Q: Can I use features such as HTML, CSS, and JavaScript in my
messages?

If you post your message using the Google Groups web interface you
can not use for example HTML, CSS and JavaScript in your message so
that they would work. Instead, they will be shown as text in your
message.

If you send your message via email, you can not use for example HTML,
CSS and JavaScript in the message body. But if you send an HTML file
as a file attachment, Google Groups web interface should support some
of the HTML features, but it will remove for example <bgsound>,
<embed>, <iframe>, <object>, and <script> tags, so you can't use for
example JavaScript or embedded videos with your messages, but you
should be able to use "inline style CSS" (CSS that is defined for
example in a paragraph tag). In addition to attaching an HTML file to
your email message, your email program/service might use HTML in the
messages, but in that case you may need to look for a "Send as HTML"
or "Rich Text Format" or a similar kind of setting. You may need to
experiment with your settings a little.

A possible reason why some tags in HTML are removed might be because
of security issues, because for example <embed>, <iframe>, and
<script> tags could be used to infect computers with viruses.