wbmp

from The Free On-line Dictionary of Computing (8 July 2008)

wireless bitmap
WBMP

   <graphics, file format> (WBMP) A {bitmap} for display on a
   {WAP} mobile phone.

   Currently (2001) the only type of WBMP file defined is a
   simple black-and-white {image} file with one {bit} per {pixel}
   and no {compression}.

   [WAP Forum (http://wapforum.org/), "WAP-190-WAE-Spec" or
   "Wireless Application Protocol, Wireless Application
   Environment Specification"].

   (2001-05-23)