With the continuous revelation of the MLS rules regarding player acquisition, I've developed the flow chart below to (hopefully) help make sense of it all. There are examples now of nearly everyone of these circumstances, whether it be Bradley and Dempsey with their MLS paid transfer fees, Maurice Edu with the club paid transfer fee or one of the many other players who've entered league via these various mechanisms over the years. While it seems like we have all the ifs, ands or buts covered, it always seems that some new rule comes along to surprise us. While this is accurate as of 1/14/2014, there may be any number of changes in the future as the league further "develops" it's rules.
I corrected a missing item regarding non-DP USMNT or sold players.
Any questions, errors, or WTFs? Let me know in the comments