This state indicates that the object in question implements some form of typeahead or pre-selection behavior whereby entering the first character of one or more sub-elements causes those elements to scroll into view or become selected.
Subsequent character input may narrow the selection further as long as one or more sub-elements match the string. This state is normally only useful and encountered on objects that implement Selection. In some cases the typeahead behavior may result in full or partial completion of the data in the input field, in which case these input events may trigger text-changed events from the source.