My website’s script utilize: VENDOR PROPRIETARY EXTENSION <config>.

 

I want to have my website conform to having valid HTML. Please help me...

A good place most people start is:
http://validator.w3.org/

That way it can tell you specifically what's wrong and you can work out the bugs there. (e.g. tells you the line number in the code to change)

If you mean -webkit-box-shadow and others, don't worry if they don't validate.

 

However, you can check whether they are still required for your particular style here

http://caniuse.com/#index

 

as some browsers have updated and don't need a prefix now for some styles, but will still require them for other styles.

 

See http://reference.sitepoint.com/css/vendorspecific

Edited February 16, 201313 yr by Wickham