You could also add that vegetation, if specifically mentioned,other than as a perch for the bird, must be unusual i.e. apples growing on an ivy tree, roses changing colour from red to white when placed on a grave etc.If inland, water must always be either :a) wide and deep, or b)fast flowing to sweep the body away.
If the sailor is to have the required sexual prowess he must be a rating, not an officer, otherwise the rule about lords and general wimpyness apply.
If the sailor is leaving his own true love it must be for a good length of time, like twenty five years. Two weeks in Bognor won't do. Naturally, the true love must remain true during this time, unless of course the sailor returns early, when it is mandatory that he catches her with another man or is told she is gone to be wed to another. The true love then ceases to play this role and instead becomes The False Jade.
This is brilliant fun! Mo