ICBM address n.
(Also `missile address') The form used to register a site with the Usenet mapping project, back before the day of pervasive Internet, included a blank for longitude and latitude, preferably to seconds-of-arc accuracy. This was actually used for generating geographically-correct maps of Usenet links on a plotter; however, it became traditional to refer to this as one's `ICBM address' or `missile address', and some people include it in their sig block with that name. (A real missile address would include target elevation.)