Socket Mobile SDIO - Manual (Page 65)

5. Your mobile computer will connect to your phone and begin dialing.
Note: The Socket Dialer can dial a phone number containing any of the
17 following non-numeric characters:
* # + . / ! @ - \ space A B C D T P W
Additionally, the following string can be included in a phone number:
(‘,’)
The Socket Dialer can not dial a phone number containing non-numeric
characters other than those listed above.
Socket recommends that you follow the standard Microsoft Outlook
format for phone numbers.
CHAPTER 6: THE SOCKET DIALER | 65