an Entity references as follows:
The heir apparent or heir presumptive to a Scottish peerage is known as a Master, or a Mistress if the heir is female. The heir's style is "The Master of [Peerage]" or "The Mistress of [Peerage]". If the master is an heir apparent, and the peerage has a subsidiary title that could be used as a courtesy title, then the styling of Master is usually forgone. However, if the person is an heir presumptive, or if the peerage has no subsidiary title, then Master/Mistress is a common styling. However, because the word Mistress is quite archaic, many women choose not to use the style Mistress and instead use the regular styling, e.g. Lady Mary Smith or The Honourable Mary Smith.