11. The semicolon is always followed by a lower-case letter.
Proper nouns are the only exception. You would be correct to say: Mark and Janet are picking a name for the baby; Mark Junior is on the list. You would not say: Mark and Janet are picking a name for the baby; It’s going to be a boy.
12. Semicolon use can be applied to separate two clauses or sentences that are saying the same thing in different ways.
Semicolons are very poetic when used in this fashion. You have the benefit of connecting the same thought said two different ways: I love the smell of peonies; they make the room smell fresh.