In some cases, say when displaying a list of telephone numbers, it would be great to have a functionality where you could "link" directly to the telephone number just by selecting it. The connection would then close, and the telephone would automatically dial the new number, for instance by doing a dial:12345678 very much like the tag of the HTML world.

This functionality is being incorporated by more and more browsers, but not all - yet. Openwave, Mitsubishi and Ericsson has incorporated this functionality into their browsers based on the Wireless Telephony Interface specifications (WTAI). WTAI will allow the following URL when accessed to disconnect the WAP call and dial the specified number.

  <go href="wtai://wp/mc;+4712345678">Make a call to +47-12345678</go>

Nokia's 7110 (and others with a similar browser) have a function called "Use number" which will read through the current WML card looking for something that looks like a telephone number. For more information on this function, see this section.

Chapter 17 in "Professional WAP" from Wrox