Cannon/Canon: Used to established limits/rules

Law of the Sea/Law of the Land?

The cannon-shot rule is said to have been first mentioned by the Dutch delegation at the London Fisheries Conference in 1610. In May of 1609, King James I had issued a proclamation prohibiting ‘strangers’ from fishing in waters claimed as British seas. The underlying consideration of the Netherlands was therefore to find an argument that would allow their seamen to continue to sail to the fishing grounds as unrestricted as possible. Against this background, the Dutch delegation in London thus claimed that:

For that it is by the law of nations, no Prince can challenge further into the sea than he can command with a cannon except gulfs within their land from one point to another.

https://legalhistoryinsights.com/the-cannon-a-tool-for-delimiting-maritime-space/

CANON, eccl. law. This word is taken from the Greek, and signifies a rule or law. In ecclesiastical law, it is also used to designate an order of religious persons. Francis Duaren says, the reason why the ecclesiastics called the rules they established canons or rules, (canones id est regulas) and not laws, was modesty. They did not dare to call them (leges) laws, lest they should seem to arrogate to themselves the authority of princes and magistrates. De Sacris Ecclesiae Ministeriis, p. 2, in pref. See Law, Canon.

LAW, CANON. The canon law is a body of Roman ecclesiastical law, relative to such matters as that church either has or pretends to have the proper jurisdiction over:

2. This is compiled from the opinions of the ancient Latin fathers, the decrees of general councils, and the decretal epistles and bulls of the holy see.

https://legal-dictionary.thefreedictionary.com/canon