In reply to wercat:
I guess you meant parentheses rather than something like 'parameters'? In which case I suppose you meant that the ambiguity – to put it in terms of symbolic logic – is the confusion between:
Overtime is not payable for (harvesting v packing v distributing)
OR:
Overtime is not available for ((harvesting v packing) v distributing).
[Though the outer brackets aren't really necessary.]
The beauty, though, is that all this can be done perfectly clearly with the correct use of commas rather than the logical clumsiness/overkill of brackets.
Post edited at 19:22