by RWSmith » Tue Oct 11, 2011 2:50 pm
If you are referring to merit badges by "Field of Study" (also sometimes referred to as "Field of Activity"), that's been the BSA way since "the beginning"... when a Scout was required to earn "X" merit badge(s) from a "X" field prior to advancing to "X" rank.
With requirements changes over the years, it's nothing more than a carry-over from the olden days and holds no advancement requirements significance TODAY... now-a-days, Eagle-required MBs are specified, individually.
Even so, BSA still categorizes all (including new) merit badges by field; and, frankly, it is a good reference for Scouts, leaders, and parents.