LN: http://surnames.behindthename.com/names/usage/scottish
SO: FN is from here:
http://www.behindthename.com/names/usage/british MN begins with I, O or U.
SO: FN ends in -ie. MN is a surname and begins with B or L.
DS/DD: FNs are from here:
http://www.behindthename.com/names/usage/history MNs are nature related.
DD: FN is Finnish. MN is both French and English.
DS: FN is a town or city name. MN is from here
http://en.wikipedia.org/wiki/List_of_Presidents_of_the_United_States#List_of_presidentsDD: FN is 4 letters long and ends in -a. MN is an uncommon virtue name.
DD: FN is Cornish. MN is biblical but doesn't end in H.