Starting with Ver6, there is no longer a distinction between full-width and half-width characters. In Ver5, for full-width characters, you had to specify Pos as two characters, but from V6 onwards, both full-width and half-width characters can be counted as one character.
 
Example)

If you want to get "efg" in Ver5
var a = ::MidStr("abcaefg", 5);

If you want to get "efg" with Ver6
var a = ::MidStr("abcaefg", 4);

Starting with Ver6, there is no longer a distinction between full-width and half-width characters. In Ver5, for full-width characters, you had to specify Pos/Num as two characters, but from V6 onwards, both full-width and half-width characters can be counted as one character.
 
Example)

If you want to get "if" in Ver5
var a = ::MidStr("abcaiefg", 5, 4);

If you want to get "if" in Ver6
var a = ::MidStr("abcaiefg", 4, 3);