I was at the factory outside of Seoul for about 10 days straight since moving, and didn't get a chance to go report my new address to the Immigration Office. I almost forgot, until last night I suddenly remembered. First thing this morning, on the last day (you get 14 days to change without penalty), I went down to get it changed. It really wasn't any big deal, but when she handed me my card back, she showed me the new address, and it wasn't anything like the address I had given on the form! I didn't want to question it (don't rock the boat with Immigration, is my motto). On returning to the office, I asked CH about this, and he said that this was a new form of address that the government was adopting, although it wasn't widespread.
Well, for all these years in Seoul, I had finally gotten used to the address system. Now they're changing it? Did a little research online, and found this post from 2004 (!) describing the new address system, which is like we have in the USA. Street names, street numbers with odd and even numbers on opposite sides of the street. Wow, this has been around since 2004? Here is the official website, you can translate an "old" style into the "new" style, and also see a map showing street names and house/building numbers. But wow, at least 6 years going and it's still not popular?