Add as many custom values as you want, or define static fields which are always visible.
Arbitrary section
add_term_meta
add_term_meta( $term_id, $meta_key, $meta_value, $unique = FALSE )
update_term_meta
update_term_meta( $term_id, $meta_key, $meta_value, $prev_value = '' )
delete_term_meta
delete_term_meta( $term_id, $meta_key, $meta_value = '' )
get_term_meta
get_term_meta( $term_id, $key, $single = FALSE)
