Why do the notice use "may not" instead of "shall not" or bait ban?
Great question!
I hope I can answer it for you satisfactorily.
"Shall" derives from Old English 'scalt' which meant "should" or "must", and it expressed a moral obligation deriving from God's and other people's expectations. (think the Ten Commandments in the Bible). As such, it is still retained in very formal English, especially in contracts.
However, modern times require a more modern approach to language, so "shall" is being taken by the vast majority of the population as a synonym of "will". "Will", as a modal of future, conveys a prediction or assumption on the part of the writer/speaker that something is to take place at some later time, but it does NOT convey prohibition. Therefore, it is not really the best modal verb to use on a modern fisheries' notice.
The modal verb '
may' has more than one use. In its most simple application, it conveys probability, but in formal language, its primary use is for giving or denying PERMISSION to do something.
For example, If you wanted to ask a CO if you are legally allowed to fish a section of a river, you would ask, "May I fish here?", and not "Shall I fish here?", correct?
So when the notice states 'anglers
may not retain pink and sockeye salmon', it clearly means anglers are prohibited BY AUTHORITY AND/OR LAW to harvest pink and sockeye salmon, whereas using 'shall not' would merely state the writer's prediction, assumption or expectation.
Now if someone is really inclined to go much deeper into the reasons why the modal SHALL really sucks when it comes to legalities, find the time to read this fantastic article on the issue:
http://www.koncision.com/wp-content/uploads/2011/05/nylj-shall-101807.pdfCheers, Milo