The Playing Conditions Calculation (PCC) was something brand new to the United States when it was unveiled with the World Handicap System in the Rules of Handicapping in 2020.
The PCC determines whether playing conditions on the day of play differed from normal conditions to the extent that an adjustment is needed to compensate. Factors such as course conditions, weather conditions, or course set-up can contribute to a PCC adjustment being needed.
The automatic system calculation occurs once per day, using scores posted from both genders and all sets of tees at a course on a given day. If a player posts a score for that date on a subsequent day, they will receive the calculated PCC.
A PCC Calculation can range from -1 to +3 in integer values, -1 when the course plays easier than the rating and +1, +2, or +3 when more difficult. When calculating the handicap differential for the day, the PCC adds or subtracts from the course rating. Thus, if a course has a rating of 70.0 and observes a PCC of +2, the differential calculation uses a value of 72.0 for the rating.
On a player's record in the GHIN products, PCC is clearly indicated next to the C.R. and Slope:
As shown with the example above, PCC for 9 hole rounds is half of that of an 18 hole round (+2 on the 18 hole round on 2/20/21 and +1 on the 9 hole round that is waiting to be combined).
More detailed information on PCC can be found in Rule 5.6 (page 54) of the Rules of Handicapping