An empty variant, a single negative value, a single index value, or an array of zero or more index values (negative index values are legal but will be ignored).

If the Selector argument is a non-negative scalar value, then SourceFlags of the indicated feature from the collection is exposed or set as a scalar Long value.

If the Selector argument is a value of negative one (-1), then SourceFlags of all features from the collection are exposed or set as a scalar Long value. The property will be the OR'ed SourceFlags flags of all features in the collection.

If the Selector argument is missing or any negative value other than minus 1, then the Selected property is exposed or set as an array of Long values, one for each feature. The number of elements in the array will be equal to the Count property.

If Selector is an array, then zero or positive values are treated as indices into the features collection, negative values are legal but ignored. In this case, the SourceFlags will be exposed or set as an array of 'Long' values equal to the length of the number of non-negative elements in the Selector array. Index values greater or equal to the Count property are illegal.

A mask for the flags being set or accessed. Default value is -1 (all bits are exposed or set).