This section of ISOM2000 was replaced eith ISSOM in February 2003 - see here
8.1 General

The park orienteering discipline is still under strong development. This makes it difficult to create a fixed standard, since doing this could harm the further development. Therefore the word "guidelines" has been chosen, meaning it is not to be considered as an enforcing standard, simply because map making in town and park environments often needs improvisation and compromising. The "guideline" indicates a least common denominator, making sure that certain basic cartographic rules and language is maintained.

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