exclusive or designator
См.: исключающее обозначение 'или'.
exclusive 'or' designatorexclusive 'or' designator - - A symbol using the word OR enclosed by "< >" (i.e., <OR>) that, when placed between two causes of a single effect signifies mutually exclusive causes. When placed between causes of a single effect it means that if one cause happens, the other cause does not.
Illustration 1: Exclusive OR (cause)
Illustration 2: Exclusive OR (effect)