[Dx4win] Errors in country file

[Alain, F 5 L I W]

Hello all,
I update my country file myself but I never used File | Check for errors in
the Country editor.
I try this function today for the first time and I get some lines like that
:
M-start < C-start YU 4N
M-start < C-start YU6 4N3
Overlap S5 4N3 
Overlap UA9 RS0
I don't have many errors but it's concern mainly YU, YU6 or 4N callsigns
(Yugoslavia ---> Serbia ---> Montenegro) and some callsigns from Russia.
How I can correct these errors (I prefer update my country file myself
because I don't need a country delete in 1950 ; I was born in 1962 ;-)) ?

73

Alain, F5LIW