An "Index" by definition means you are using the USGA formula to calculate handicaps. Handicap System follows the exact USGA formula to calculate indexes. If you are using the USGA calculation mode, a course handicap is the conversion of a golfer's Index to a course handicap and uses the following formula.
Course Handicap = Index X (Slope of Tee / 113)
A "Factor" by definition means you are using the RCGA formula to calculate handicaps. Handicap System follows the exact RCGA formula to calculate Factors. As of March 2012, the USGA and RCGA calculate handicaps the same way. The RCGA does revise a player's handicap after each round posted compared to the USGA revision schedule of 1st and 15th of the month.
If you are calculating a custom handicap, the handicap is calculated according to the custom parameters you have set up. If you select to calculate a custom handicap, neither a USGA Index nor an RCGA Factor will be shown. A Cdex will be displayed.
When you type in or import a handicap
When you are using the USGA handicapping mode, if you import in or type in a handicap and the player has less than 5 scores, the imported/typed-in handicap will remain (unless you delete it in the player information form) until the player has a minimum of five scores and the handicap has been recalculated.
Note: Handicap System looks at score dates when calculating a handicap. Thus if all your scores have the date 05/01/2013 or after and you specify a date of 04/01/2013 for the revision date, no handicaps will be calculated.
Meaning of handicaps with adjacent letters
Exceeding handicap ceiling:
J Used for USGA or RCGA 9 hole handicaps only. This indicates a "LOCAL" 9 hole handicap. The 9 hole handicap exceeds the USGA handicap ceiling. See USGA/RCGA Mode.
L Used for USGA or RCGA 18 hole handicaps only. This indicates a "LOCAL" 18 hole handicap. The 18 hole handicap exceeds the USGA handicap ceiling. See USGA/RCGA Mode.
Exceptional tournament scores:
R For USGA or RCGA handicaps: Indicates that the handicap was calculated using the alternative formula for "Reduction of a USGA Handicap Index based on exceptional tournament scores". For detailed information see section 5-2 of the USGA HANDICAP SYSTEM manual.
N Indicates a 9 hole handicap.