History of CR 506.1

Every distinct wording since 2010, newest first.

August 25, 2017 · Commander 2017
The combat phase has five steps, which proceed in order: beginning of combat, declare attackers, declare blockers, combat damage, and end of combat. The declare blockers and combat damage steps are skipped if no creatures are declared as attackers or put onto the battlefield attacking (see rule 508.8). There are two combat damage steps if any attacking or blocking creature has first strike (see rule 702.7) or double strike (see rule 702.4).
September 30, 2016 · Kaladesh
The combat phase has five steps, which proceed in order: beginning of combat, declare attackers, declare blockers, combat damage, and end of combat. The declare blockers and combat damage steps are skipped if no creatures are declared as attackers or put onto the battlefield attacking (see rule 508.5). There are two combat damage steps if any attacking or blocking creature has first strike (see rule 702.7) or double strike (see rule 702.4).
September 30, 2011 · Innistrad
The combat phase has five steps, which proceed in order: beginning of combat, declare attackers, declare blockers, combat damage, and end of combat. The declare blockers and combat damage steps are skipped if no creatures are declared as attackers or put onto the battlefield attacking (see rule 508.4). There are two combat damage steps if any attacking or blocking creature has first strike (see rule 702.7) or double strike (see rule 702.4).
June 17, 2011 · Commander 2011
The combat phase has five steps, which proceed in order: beginning of combat, declare attackers,
February 4, 2011 · Mirrodin Besieged
The combat phase has five steps, which proceed in order: beginning of combat, declare attackers, declare blockers, combat damage, and end of combat. The declare blockers and combat damage steps are skipped if no creatures are declared as attackers or put onto the battlefield attacking (see rule 508.4). There are two combat damage steps if any attacking or blocking creature has first strike (see rule 702.7) or double strike (see rule 702.4).
October 1, 2010 · Scars of Mirrodin
The combat phase has five steps, which proceed in order: beginning of combat, declare attackers,
June 18, 2010 · Archenemy
The combat phase has five steps, which proceed in order: beginning of combat, declare attackers, declare blockers, combat damage, and end of combat. The declare blockers and combat damage steps are skipped if no creatures are declared as attackers or put onto the battlefield attacking (see rule 508.4). There are two combat damage steps if any attacking or blocking creature has first strike (see rule 702.7) or double strike (see rule 702.4).
February 1, 2010 · Worldwake
The combat phase has five steps, which proceed in order: beginning of combat, declare attackers, declare blockers, combat damage, and end of combat. The declare blockers and combat damage steps are skipped if no creatures are declared as attackers or put onto the battlefield attacking (see rule 508.5). There are two combat damage steps if any attacking or blocking creature has first strike (see rule 702.7) or double strike (see rule 702.4).