In this document the search options concerning tautomers are summarized and their usage is shown in different search interfaces.
See detailed description of tautomer search here. MolSearch API
        MolSearchOptions searchOptions = new MolSearchOptions(SearchConstants.SUBSTRUCTURE);
        searchOptions.setTautomerSearch( SearchConstants.TAUTOMER_SEARCH_DEFAULT /
                SearchConstants.TAUTOMER_SEARCH_ON / SearchConstants.TAUTOMER_SEARCH_OFF /
                SearchConstants.TAUTOMER_SEARCH_ON_IGNORE_TAUTOMERSTEREO );
        // ...
        MolSearch searcher = new MolSearch();
        searcher.setSearchOptions(searchOptions);JChemSearch API
        JChemSearchOptions searchOptions = new JChemSearchOptions(SearchConstants.SUBSTRUCTURE);
        searchOptions.setTautomerSearch( SearchConstants.TAUTOMER_SEARCH_DEFAULT /
                SearchConstants.TAUTOMER_SEARCH_ON / SearchConstants.TAUTOMER_SEARCH_OFF /
                SearchConstants.TAUTOMER_SEARCH_ON_IGNORE_TAUTOMERSTEREO );
        // ...
        MolSearch searcher = new MolSearch();
        searcher.setSearchOptions(searchOptions);JChem Oracle Cartridge
Use the jc_compare operator with tautomerSearch:d/y/n/is
    d: (default) behavior is defined by the search context: tautomer search is turned on for duplicate searches in a tautomer duplicate database table; it is turned off in all other contexts
    y: on;
    n: off;
    is: ignore tautomer stereo (tautomer search is turned on but stereo information is ignored in the tautomer regions).jcsearch command line tool
Use the following command line parameter:
--tautomerSearch:d/y/n/is
    d: (default) behavior is defined by the search context: tautomer search is turned on for duplicate searches in a tautomer duplicate database table; it is turned off in all other contexts;
    y: on;
    n: off;
    is: ignore tautomer stereo (tautomer search is turned on but stereo information is ignored in the tautomer regions).