* Do not use <font> element.
* Move arrangement attributes (align, valign, width, height) to CSS.
* Do not use tables except showing table data. Using tables for visual formatting is acceptable in complex situations only. Max table nesting can not be great than 3.
* Move attribute "background" to CSS.
* Design of input fields and buttons must be written as class in CSS.
* Style table must be written as external file and linked using <link>
* All images related to design (not content) move to block with style {background: transparent url("gif") no-repeat;}
HTML code
* If table cell contains only image with width and height, then don't use these attributes for cell.
* Use minimum cols and rows for tables.
* All <image> elements must have "width" and "height" attributes.
* All <image> elements, which are not links, don't have "border" attribute.
* All attributes values must be placed in double quotes.
* All tags and attributes names must be in low case.
CSS code
* Unique elements must have "id" attribute, which is used for style. Repeated elements must use classes.
* Determine Links style through styles of (td {}, td a {}, td a:hover {}). a:hover must redefine only changed atttributes.
* Determine background color for <body>
* Split declarations to groups (fonts, tables, text blocks, divs)
* Determine geometrical dimensions in percents or pixels.
* All colors values must be as short as possible and in high case (#FFF instead of #ffffff).
* All tags and attributes names must be in low case.
* All margins and indents must be defined for all browsers.
* All classes and identifiers must be named logically with one naming convention.
Structure
* Use title, description and keywords in header.
* All elements with closing tags must have it (ideally, use XHTML 1.0 Transitional/Strict).
* Use alt attribute for <image>. If image don't have semantic meaning, alt must be empty.
* Use comments before main blocks.
* Use standard tags for creating text structure (<h1>-<h4>, <p>, <ul>, <il>, <li> and so one).
* Vertical and Horizontal menus must be defined using <li>.
* Don't use
and . Use <strong> and .
* Blocks must be placed in document in the descending order of importance. Blocks location can be defined using CSS.
You can discuss and improve this document at http://www.htmlchecklist.com/
Vadim Nareyko, CEO of CalidStyle (http://calidstyle.com/)
