Great idea! I code in the seldom-seen AHTML ('Archaic HTML'), as you all suspected.
A friend tested a page I wrote last month and found it wouldn't work on any of his 5 browsers....oh well.
Well, Elaine, if you want maximum compatibility, you should better use XHTML which adds more restrictions than it adds features. It's the old HTML which causes most troubles across distinct browsers, due to its ambiguities, or differences of implementations (frames, table formats with non-zero cell spacing and cell padding, backgrounds, column widths in percentages specified by HTML
width="x%"
attributes instead of by CSS
style="width: x%"
attributes or stylesheet rules...).
So:
(1) enforce the XML rules: close all tags (notably <p>...</p> or <li>...</li> paragraphs, and <br /> or <img ... /> and <meta ... /> empty elements), make them all properly nested.
(2) use only the standard subset of HTML elements and attributes. And make sure you don't include HTML block elements within HTML inline elements (for example <font> elements surrounding <p> paragraphs...)
(3) use simple CSS stylesheets, with only one rule per element or class. And don't overuse some advanced CSS2 or CSS3 style features. Keep some tolerance for table column widths (make sure that font sizes can be reduced or increased for accessibility).
(4) test your pages in IE-6, FireFox-1.0 (excellent!), Netscape-4 (old...), and on Mac Safari if you can: it should be enough to work well with most other browsers (Netscape 6+ should behave mostly like IE-6 and FireFox on Windows, as long as you don't need JavaScript).
