Null UW
From UNL Wiki
A semantically-empty Universal Word, used to represent exophoric referents (instantiated by pro-forms) or to hold interjection attributes. The null UW is represented as "00".
Ouch! = 00.@pain anything = 00.@any.@thing he = 00.@3.@male vous (French) = 00.@2.@polite
