At the recent Australian 3-Days, some courses had a leg from 5-6 that for many competitors (myself included) became 5-9 when the nearby control 9 was mistaken for a 6 (unfortunately it's only an obvious mistake when you look at the actual map -  I defy anyone to work out the legs by looking at the Livelox version of the M70 course for Day 1).

"How could you be so dumb?" I hear you say, and that's a fair comment, but should the controller have noted it and suggested a course change?

Identical control codes and controls within the proscribed limits

It’s unlikely to happen in Tasmania, but where clubs have their own set of SI boxes and different clubs are organizing an event on the same map (or overlapping maps) as part of a multi-day competition, it’s possible that controls could have the same control number. A more likely problem in Tasmania is that we inadvertently transgress rule 19.4 (controls shall not be sited within 30m of each other (15m for map scales of 1:5000 or 1:4000)) because different organisers use proximate features.

In such circumstances, the controller (or controllers) should look for potential problems by preparing a composite map of the controls for days when the same or overlapping maps are being used. 

Another instance where confusion can arise is the control code

Rule 19.6 states:

“Each control shall be identified with a code number, which shall be fixed to the control so that a competitor using the marking device can clearly read the code. Numbers less than 31 may not be used. 

The figures shall be black on white, between 3 and 10 cm in height and have a line thickness of 5 to 10 mm. Horizontally-displayed codes shall be underlined if they could be misinterpreted by being read upside down (e.g. 161).”   

Once upon a time, we discarded control codes that could be misinterpreted, but this is impractical with control codes affixed to SI boxes as there is a limited number of potential codes (31-255 to be precise – Why? Simple answer “Computer says no!”)

Is this an issue? – not usually, but if you have controls in close proximity (and obviously not transgressing rule 19.4), it’s best make sure that:

The control codes comply with rule 19.6 and they have distinctly different numbers so that competitors don’t accidentally punch an incorrect control, even though rule 19.4 isn’t in play.