HTML is no longer being developed. The last version of HTML was HTML 4.01. A new markup language called Extensible HyperText Markup Language (XHTML). XHTML is very similar to HTML but has a few different syntax (formatting) rules and is stricter in its requirements.
All web pages will use either the HTML 4.01 Transitional DTD or the XHTML 1.0 Transitional DTD in the <!DOCTYPE> tag (which must be the very first line of code for each web page). Alternatively, you may use the HTML 4.01 Strict DTD or the XHTML 1.0 Strict DTD.
The correct <!DOCTYPE> tags are:
HTML 4.01 Transitional DTD:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
XHTML 1.0 Transitional DTD:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
HTML 4.01 Strict DTD:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
XHTML 1.0 Strict DTD:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
The <!DOCTYPE> tag is more clearly readable separated into two lines, although all on one line is acceptable (depending on how wide your browser window is, the code lines may display on more than 2 lines).
Avoid use of deprecated HTML tags and attributes, such as the <font> tag. More about XHTML and HTML.
HTML tables may be used for layout with proper provisions made for accessibility. More about Accessibility.
Do not use HTML frames on the Ohlone College web pages. There are problems with printing, bookmarking, emailing links, and search engines with pages designed using frames. There are also accessibility issues for the disabled.
The Web Center contains articles, tutorials, and other resources for learning (X)HTML, accessibility, validation, and more.