Every distinct wording since 2010, newest first.
October 7, 2022 · Unfinity
A sticker receives a new timestamp each time it’s put on an object. If the object a sticker is on receives a new timestamp, the sticker receives a new timestamp immediately after that one. If the object a sticker is on becomes part of a merged permanent on the battlefield, the sticker receives a new timestamp at that time. If an object has more than one sticker on it as it enters a zone or becomes part of a merged permanent, the relative timestamp order of those stickers remains unchanged.
April 17, 2020 · Ikoria
If two or more objects would receive a timestamp simultaneously, such as by entering a zone simultaneously or becoming attached simultaneously, their relative timestamps are determined in APNAP order (see rule 101.4). Objects controlled by the active player (or owned by the active player, if they have no controller) have an earlier relative timestamp in the order of that player’s choice, followed by each other player in turn order.