Display of a network address is essential if one wants to be to be taken seriously by hackers; in particular, persons or organizations that claim to understand, work with, sell to, or recruit from among hackers but *don't* display net addresses are quietly presumed to be clueless poseurs and mentally flushed (see flush, sense 4). Hackers often put their net addresses on their business cards and wear them prominently in contexts where they expect to meet other hackers face-to-face (see also science-fiction fandom). This is mostly functional, but is also a signal that one identifies with hackerdom (like lodge pins among Masons or tie-dyed T-shirts among Grateful Dead fans). Net addresses are often used in email text as a more concise substitute for personal names; indeed, hackers may come to know each other quite well by network names without ever learning each others' `legal' monikers. See also sitename, domainist.
[1996 update: the lodge-pin function of the network address has been gradually eroding in the last two years as Internet and World Wide Web usage have become common outside hackerdom. -- ESR]