Isn it possible for two different ISPs to use a single code to mean different things?
Yes. This isn’t a problem for codes like “LAX” which almost universally will mean Los Angeles, CA, USA, but a code like “POR” might mean Portland, OR, USA for one ISP and Portland, ME, USA for another– and these two Portlands are 3000+ miles apart. I haven’t run into this situation so far, but, if I do, I’ll alter the list of patterns to separate these cases (eg, “POR” found in an alter.net host could be recodified as “POR.alter.net” and “POR” found in a local-maine.net host could be recofidied as “POR.local-maine.net”, so the two codes would no longer be the same). As of November, 2002, I have run into this situation, and the top few lines of the patterns file now compensate for this. 3. Map Questions 3.1. How is the map created? The blank map of the United States is a static image which I originally downloaded from the U.S. Census Bureau TIGER mapping service. The city dots and names are then added using a libgd-extension to PHP3. 3.2. Why isn’t the map in GIF format? The map is in
