Use this field if want to add something to the Title which extends or elaborates on the Main Title. Do not separate the Main Title and the Subtitle with punctuation as a colon will automatically be added.
For instance, the words 'A New History of Botswana' for the work 'Reaching for the Future: A New History of Botswana'. Do not use punctuation between the Main Title and the Subtitle. A colon will be automatically be added when the Main Title and the Subtitle appear together on the same line. Use Title Case: the first letter of the Subtitle is always a capital or Upper Case letter, as well as the first letter all words other than definite and indefinite articles (e.g. 'the' and 'a'), conjunctions (e.g. 'and'), and prepositions (e.g. 'in', 'of' etc.).