These apply mostly to ballads:

11. True loves are always either:

a) Missing (gone for seven years)
b) Dead (see Necrophilia element)
c) In disguise
d) Your brother/sister (either known or unknown)
e) False (off chasing/married to another)

If it's a happy ending, it's a very rare folksong...

12. If your true love is dead, you must:

a) Long to kiss his/her dead lips or other portions of the anatomy (The Tradition of Necrophilia)
b) Never love again
c) Have done her in yourself after spending all night diggin' of her grave
d) Have done him in yourself because he done you wrong

13. If you are a sailor, and you meet a fair young lady, you will:

a) Wind up with no money and no clothes, wearing a dress (the Transvestite Element)
b) Get laid after pulling her string
c) Acquire a painful and unpleasant social disease
d) Get shot after she dresses in men's clothing and finds you've been false (see 11-e, 12-d and Transvestite Element)

14. If you are a young lady, and you meet a sailor, you will:

a) Turn him down because he's dirty
b) Turn him down because you don't recognize him (see 11-c and 12-b)
c) Change your mind when you find out he's got money (see 13-a)
d) Change your mind after experiencing his sexual prowess (see 13-b)
e) Dress up in man's clothing (the Transvestite Element, yet again)

More as I think of them...This is fun!