History of CR 605.3c
Every distinct wording since 2010, newest first.
May 3, 2019 · War of the Spark
Once a player begins to activate a mana ability, that ability can’t be activated again until it has resolved.
January 25, 2019 · Ravnica Allegiance
Once a player begins to activate a mana ability, that ability can't be activated again until it has resolved.
July 22, 2016 · Eldritch Moon
Once a player begins to activate a mana ability, that ability can’t be activated again until it has resolved.
February 1, 2010 · Worldwake
rule 605.3c not present in this release