I bought the Survival Guide hardcover edition and noticed the big map that came included with the guide. The guide breaks the Boston area up in different regions with different names. I wanted these regions and their number to show inside my Pip-Boy as well for a bit more easy navigating so I edited the original map. The region numbers are the same as in the Guide. If you don't have the guide yourself, in the lower right corner you can find the names of the 18 different regions.