User-Agent: Opera/9.24 (Windows NT 5.1; U; en)
I see the default doctype that Composer uses is HTML 4.1 Transitional with charset iso-8859-1. There are more modern doctypes and charset that the W3C recommends and I think the default should be XHTML 1.0 Strict and UTF-8. The UTF-8 charset is especially important because with iso-8859-1, only western european languages work properly. Any other language breaks with iso-8859-1. So if you really want to keep HTML 4.1, at least use UTF-8 as default.
Steps to Reproduce:
1. Open Composer
2. Click the "HTML Source" tab
HTML 4.1 Transitional + iso-8859-1
XHTML 1.0 Strict + utf-8
[Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.9b4pre) Gecko/2008022601 SeaMonkey/2.0a1pre] (nightly) (W2Ksp4)
Confirming, but morphing to the charset issue only;
the doctype issue is bug 92525.
The charset can be edited in the Source View,
but is reverted to ISO-8859-1 when changing view,
and, this, without any warning :-<
I was able to get successful validation via W3C validator by updating ~/template/en/default/global/header.html.tmpl as follows:
Locate the following lines ...
<title>[% title %]</title>
Insert this line immediately after ...
<meta http-equiv="Content-type" content="text/html;charset=UTF-8">