in Delphi TIPS
In Delphi, sets or set types allow you to do set type operations like union, intersection and difference on a set of ordinal values. A set is a collection of ordinal values. The values in a set have no order and it makes no sense to have a value twice (or more times) in a set. Since strings are not ordinal types you cannot have set of string declarations. Or, can you?
Read the full article to learn how to Mimic The Functionality of "set of string"