做Xhtml+CSS页面，不推荐使用的标签代码，请尽量不要使用这些HTML标签：

Do not use these html elements in html pages.
Presentational elements should not be used.
Support for some elements has been (or will be) deprecated; they should not be used.

Don't Use These Tags

Presentational 
 b big
 hr
 i
 small
 sub
 sup
 tt
 Deprecated
 basefont
 center
 dir
 font
 isindex
 menu
 s
 strike
 u