Hello Adfodo,
Welcome! Actually, there are a few HTML specifications.
The latest version number is HTML 4.01. Then you have
"Transitional" and "Strict". I personally use XHTML 1.0 Strict,
but for backwards compatibility, there is XHMTL 1.0 Transitional.
And let's not forget XHTML 1.1 - that's the strictest of the
XHTML subsets so far. On my site,
Web Standards in Design
I use PHP to server either
XHMTL 1.0 Transitional or
XHMTL 1.1
- depending on the browsers ability to render standards compliant
markup or not (Internet Explorer).