Microbrowsers do not have a lot of display area to spare, so WML documents are divided into cards that are displayed one at a time. A WML document is called a deck of such cards. A deck begins and ends with the <wml> tag, and each card in a deck begins and ends with the <card> tag. When a microbrowser reads a WML document, it reads the whole deck, although you see only one card at a time.
As you'd expect, you start WML documents with this XML declaration:
<?xml version="1.0"?> . . .
As with XHTML, WML uses a <!DOCTYPE> element with a formal public identifier, except that this time, the authorization body is the WAP Forum, not the W3C:
<?xml version="1.0"?> <!DOCTYPE wml PUBLIC "-//WAPFORUM//DTD WML 2.0//EN" "http://www.wapforum.org/dtd/wml20.dtd" ...