[Koha] Mapping fields to "ignore"

Hi all, We are doing some tests to see if Koha is the right choice for our small social justice library. Does any of you know if there is a quick way to set all the MARC fields/subfields to "ignore" in the MARC structure for a given framework? I would like to do that and then map only the fields that we are going to use. Thanks! Gianmarco S. SFPIRG Social Justice Library