Since the different WML specifications contain a large number of new/updated functionality, it’s nice to know which version of WML the device you are sending WML code to supports. James Skinner has found that devices that support WML 1.2 should (or rather must) add a version number in the so called Accept header send to the web server which the request. In more detail, the version number appears after string text/vnd.wap.wml

A WML 1.1 device will an Accept header looking something like this:

Accept: image/vnd.wap.wbmp, text/vnd.wap.wml, */*

..while a WML 1.2 device will send a header looking something like this:

Accept: image/vnd.wap.wbmp, text/vnd.wap.wml;level=1.2, */*

…indicating that this is a device that accepts WML 1.2 code.

The Accept header can be read by just about any script language, such as PHP.