"%NAME( )" is a Dialog Processing Statement. This adds the name of the CharacterData in place.
%NAME(Character)
%NAME() (uses "c0" as character)
The character part defines the character whose name is supposed to be used.
This should be a valid CharacterData > CharacterKey and can also be x0 > c0 and "player".
If left empty it will automatically add "c0".
If no CharacterData is found the expression is treated as lua code that should result in a valid CharacterData > CharacterKey.