NetStumbler.org Forums

[For the Newbie or Software FAQ forums]
Can someone point me in the right direction for a list of icons in Netstumbler 4.0 and the meaning of a black diamond icon: Under NetStumbler’s list of SSIDs in my area, for example, my base station appears with a green dot. Periodically there is a dotted line from the SSID list to a green dot with my correct MAC address as well as a dotted line to a mysterious black diamond. I’ve checked the documentation (i.e., help, user interface) as well as various forum links and FAQs and done a search on various key words without avail. Next time I'll take a screen shot.

Ideas? Explanation is welcome. Thanks to more experienced users.

Base station involved: Buffalo/Melco AirStation w/ local router (U.S. model)