Add Doctype to the Front Page Default Template

FP 2003
C:\Program Files\Microsoft
Office\Templates\1033\Pages11\normal.tem\normal.htm
FP 2002
C:\Program Files\Microsoft Office\Templates\1033\Pages\normal.tem

FP 2003 gives you a choice of doctypes to enter somewhat automatically.
You can edit what's available and add your own stuff too.
Just do Tools > Page Options > Code Snippets.

In case you were wondering what a doctype declaration is.
oriellynet.com

From Thomas Brunt,
http://www.outfront.net