And you must keep all the element tags and all their attributes in lowercase, although values and content can be in any case. Attribute Values Must be Enclosed within Quotes HTML allowed skipping the quotation marks around attribute values. This will not work with XHTML MP as all attribute values must be enclosed within quotes??”either single or double. So this will not work:
Let things be centered!
It must be written as:
Let things be centered!
Attributes Cannot be Minimized Consider how you would do a drop down in HTML:
The same drop down in XHTML is done as:
The "selected" attribute of the "option" element has only one possible value and, with HTML, you can minimize the attribute and specify only the attribute without its value.