The purser said that the dragon's name was Mrs. Scrivener-Yapling, with a hyphen.
But if the word "part" or the word "share" follows, the hyphen is not used; as "two third parts."
The hyphen is used also when the words are inverted; as "four-and-thirty," "six-and-fortieth."
The hyphen is used between the component parts of some compound words.
There is no rule to distinguish the compound words that take a hyphen from those that do not.
In these words the pronunciation is more clearly marked by inserting the hyphen.
He belonged to the branch of the family that owns the hyphen and most of the money.
The word 'nightcap' is spelled with and without a hyphen in the text.
When used as adverbs they may be printed in italics without the hyphen.
The use of the hyphen does not seem to be regulated by any uniform practice.