It' like schedule key for a parameter. To preserve standard in the company, we need to minimize user to create their own version of the standard. In a simple case, a different user can spell the same parameter value differently, user A spell Gypsum Board as "GYP Board" and user B spell as "GYB". Off course some company has like the list to prevent this to happen. But it takes time to control manually and also it would be nice if we can somehow refer parameter value to a .csv/.txt file, the User just needs to choose within the list inside a .csv/.txt file. See Keynote referring system to be exact.