[Lucent] [Wavelan] and [Orinoco] cards (at least) have a proprietary mode for peer to peer operation without an [AccessPoint], usually referred to as ''ad hoc mode''.

Since [firmware] revision 6.06 (i think?), this has been supplemented by a proper, standards-compliant [IBSS] mode.

Some of the drivers still allow you to use the proprietary ad hoc mode, for example by setting the driver parameter ''mode=3''.

there's really no reason to use this any more.  if you have a card with the older firmware (like, version 4.x), you can get the proper [IBSS] mode by upgrading the firmware.  as a bonus, this will let you talk to other, non-[Lucent]/[Orinoco] cards without an AccessPoint!