Rules glossary
↑ Parent rule: 702.124 Partner
702.124i “Partner—[text]” means “You may designate two legendary cards as your commander rather than one if each of them has the same ‘partner—[text]’ ability.” The “partner—[text]” abilities are “partner—Character select,” “partner—Father & son,” “partner—Friends forever,” and “partner—Survivors.”
No sub-rules.