def skipExport(item, all, metadataProperty):
    """
    Determine whether a particular item should be exported as part of this export run.

    :param item: the item we're checking
    :param all: whether or not we're exporting all or recent items
    :param metadataProperty: the metadata property that acts as a flag to check previous exports
    """
    return not all and item.get('meta', {}).get(metadataProperty)