The 2008 CIVL Section 7A FAI Sporting Code states:

5. 5.4 Pilots Who Do Not Fly

A pilot who did not fly scores zero and is indicated DNF on the score sheet. A pilot who is disqualified will be indicated DSQ on the score sheet for all subsequent tasks. A pilot who withdraws due to illness or accident shall be marked as ABS (absent) for all subsequent tasks and no longer counted in the group or class for the purposes of scoring.

The FS Scoring Program Guide, used to score CIVL sanctioned category I and II meets, states:

http://fs.fai.org/cgi-bin/trac.fcgi/wiki/FS Guide 

After checking tracklogs, set status for those not having tracklog. Most will probably be minimum distance, this is done by just setting the pilot status to DF. Remember to set ABS for those not present at takeoff, or DNF for those that chose not to fly for some reason. ABS does not influence the scoring, while DNF ‘’does’’ influence the scoring by reducing day quality.

The Australian Competition Manual at http://www.hgfa.asn.au/ states:

5. 1 DNF- Did Not Fly

Pilots that do not launch due to safety concerns will be scored DNF (which devalues launch validity) and given a score equal to bombout score on the day. By default, the RACE scoring program scores DNF as zero. To correct this, negative penalty points must be awarded, equivalent to bombout points.

5. 2 ABS – Absent

Pilots who do not present themselves to launch are scored ABS. They will score zero for the day and they do not affect validity. In some circumstances, pilots scored as ABS will receive negative penalty points. See “closing of launch to particular grading of pilots” refer 3.13 for details.

First, there is a contradiction between the CIVL Sporting Code and the CIVL scoring program on the criteria to be used to determine ABS (absent). The Sporting Code says that the pilot has to have withdrawn from the competition. The FS scoring program says that the pilot just has to not be present at takeoff. Perhaps they want to get this better defined and agreed upon.

Second, what does withdrawn mean? Official notice? Withdrawn, just by not showing up? Withdrawn for a reason other than illness or accident? When does this occur?

Third, what does "not present at takeoff" mean? Not in the launch line? Not set up? Not on the hill? Not at the takeoff/launch point, the actual last spot where you start your run? If at a tow meet, not on the cart? Not at the flight park? Not at the airport (say at Big Spring)? Just not willing to launch?

Fourth, what constitutes a safety concern? A stated concern by the pilot or the meet or launch director at the launch point with the pilot hooked in and ready to launch? A hang over? Food poisoning? Sickness on the pilot's part? Is a safety concern anything a pilot says it is, or a launch director? Which one?

Do you have to setup to be able to have a safety concern? Do you have to be in line? What does it take to get a DNF, not an ABS?

Fifth, why under the Australia scoring system is the day devalued by the DNF and not by the minimum distance (as though the pilot had flown)?

There is some discussion of this issue here: http://fs.fai.org/cgi-bin/trac.fcgi/ticket/58.