Both The Definition of “Hole” prescribes these dimensions in both versions of the Rules.
Now Currently, under Rule 16-1c [The Putting Green: Repair of Hole Plugs, Ball Marks and Other Damage], you are permitted to repair an old hole plug or damage to the putting green caused by the impact of a ball. However, you are not permitted to repair any other damage to the putting green that might assist you in your subsequent play of the hole. On the other hand, under new Rule 13.1c(2) [Putting Greens: Improvements Allowed on Putting Greens: Repair of Damage], you will be permitted to repair not only hole plugs and ball marks, but also spike marks, scrapes or indentations caused by equipment or the flagstick, animal tracks or hoof indentations, and embedded objects, such as a stone or acorn.
Then Currently, Rule 27-1c [Ball Not Found Within Five Minutes] limits the search period to five (5) minutes. Within the new Rules, the Definition of “Lost” is “The status of a ball that is not found in three minutes after the player or his or her caddie … begins to search for it.”
Now Note 2 to current Rule 24-2 [Immovable Obstruction] states, “If a ball to be dropped or placed under this Rule is not immediately recoverable, another ball may be substituted.” In 2019, per Rule 16.1b [Abnormal Course Conditions (Including Immovable Obstructions)], when taking relief from an immovable obstruction, you may substitute another ball regardless of where the original ball may be located! See also new Rule 14.3a [Dropping Ball in Relief Area: Original Ball or Another Ball May Be Used] which reads, “The player may use the original ball or another ball. This means that the player may use any ball each time he or she drops or places a ball under this Rule.”
Now Current Rule 17-3c [Ball Striking Flagstick or Attendant] advises, “The player’s ball must not strike … (t)he flagstick in the hole, unattended, when the stroke has been made on the putting green.” According to new Rule 13.2a [Leaving Flagstick in Hole], you may make a stroke from anywhere with the flagstick left in the hole and, if the ball strikes the flagstick, there is no penalty provided you did not deliberately move the flagstick to a position other than centered in the hole.
Then Under the “Now” Rules, you may use any club to measure the specified one or two club-lengths when taking relief. The only restriction, per Decision 20/1 [Club to Be Used in Measuring], is that you must continue to use the club you originally used for measuring for all measuring in a given situation. Under the “Then” Rules, the term “club-length” is defined as “The length of the longest club of the 14 (or fewer) clubs the player has during the round … other than a putter.
Neither Currently, per Rule 20-2a [Dropping and Re-Dropping: By Whom and How], you must drop the ball from shoulder height when standing erect. Per the forthcoming Definition of “Drop,” in taking relief, you must let go of the ball from a location at knee height. This requirement is repeated in new Rule 14.3b(2) [Ball Must Be Dropped Straight Down from Knee Height Without Touching Player or Equipment].
Then Forthcoming Rule 13.2a [Playing Your Ball in Bunker: Removing Loose Impediments and Movable Obstructions] states, “Before playing your ball in a bunker, you may remove loose impediments and movable obstructions.” Currently, Rule 13-4 [Ball in Hazard; Prohibited Actions], you may not touch or move a loose impediment lying in or touching the hazard when your ball is in the same hazard.