www.merriam-webster.com/.../may
4 = shall used in law where the sense, purpose, or policy requires this interpretation
www.merriam-webster.com/.../law
1a (1) : a binding custom or practice of a community : a rule of conduct or action prescribed or formally recognized as binding or enforced by a controlling authority
www.merriam-webster.com/.../rule
1 a : a prescribed guide for conduct or action
so, rules on swimming are the laws on swimming and the laws may or shall be enforced.
we are talking about rules and laws, not "mother may i take 3 baby steps"
www.merriam-webster.com/.../may
4 = shall used in law where the sense, purpose, or policy requires this interpretation
www.merriam-webster.com/.../law
1a (1) : a binding custom or practice of a community : a rule of conduct or action prescribed or formally recognized as binding or enforced by a controlling authority
www.merriam-webster.com/.../rule
1 a : a prescribed guide for conduct or action
so, rules on swimming are the laws on swimming and the laws may or shall be enforced.
we are talking about rules and laws, not "mother may i take 3 baby steps"