DIRegEx: used for RegEx (regular expressions) search. asoRegEx search option is available only when this library is compiled in. After you install this library, enable its usage in file ATStreamSearchOptions.inc, uncomment the "REGEX" define.
Tnt Unicode Controls: used for search in Unicode-named files (TTntFileStream class is used). After you install this library, enable its usage in file ATStreamSearchOptions.inc, uncomment the "TNT" define.