How does IsIndex() and IsFavorite() determine whether a symbol is an index or favourite?

How does the AFL function IsIndex() and IsFavorite() decide whether a symbol is an index or not? When I import a new symbol, the ASCII file does not specify whether the symbol is index or not. Same goes for favourite. How does Amibroker know?

I guess by the options you can set in each of the symbol in the Information window:


Object model and "Types" for information fields can be found at: