@Override
    public String toUserDisplayableString(final int level) {
        if (!isFiltering()) {
            return null;
        }
        final StringBuilder sb = new StringBuilder(getType().getUserDisplayableName());
        if (level <= 2) {
            final String userDisplayValue = getUserDisplayableConfig();
            if (userDisplayValue != null) {
                sb.append(": ").append(userDisplayValue);
            }
        }
        return sb.toString();
    }
Base implementation for common (non-logical) geocache filters
main/src/main/java/cgeo/geocaching/filters/core/BaseGeocacheFilter.java