Another name: culture-specific items (anAsor-e vAbaste be farhang-e khAss)
I have advised a thesis on the same topic done by Miss Shabani Rad at Allameh Tabataba'i University. She worked on two other aspects which seem to be more fruitful than yours! Culture-specific items ususally cause 'lexical gap' or 'semantic void' in translation. She analyzed/categorized strategies (or procedures) of translating such items (see Newmark, a Textbook of translation on the strategies/procedures of translation). She also categorized the semantic domains of such items. By trying to determine the features of such items you reach nowhere! (I think, linguists who know little about translation studies have pushed you into this useless job!) If you want further information, contact me.