All titles in this version of Harvard style should be in sentence case. That is, you should format the title the same way you would format a sentence and only put a capital letter:
- On the first word of the title (subtitles do not get a capital letter on the first word)
- On any proper nouns (e.g. names of people, places, business, projects, etc.)
- On the names of journals - these are treated as proper nouns like company names.
The formal title of a complete published work goes into italics. For example, the title of a book, journal, legal act, film, artwork (see more here).
The title of a section of a work does not go into italics. It has single quotation marks. For example, the title of a book chapter, journal article, individual poem, episode of a TV show, etc.
This is an example of a chapter in an edited book:
Holmes K and Mair J (2018) 'Events, festivals, and sustainability: the Woodford Folk Festival, Australia', In Brinkmann R and Garren SJ (eds) The Palgrave handbook of sustainability: case studies and practical solutions, Springer International Publishing, Cham, doi:10.1007/978-3-319-71389-2_31.
Note that the title of the chapter is in 'single quotation marks' and the name of the festival and country have capitals, but not the rest of the title. The title of the book is in italics, and the name of the company has a capital letter, but the rest of the title does not.
Here is an example of a journal article:
Russo-Netzer P, Sinai M and Zeevi M (2020) 'Meaning in life and work among counsellors: a qualitative exploration', British Journal of Guidance & Counselling 48(2):209-226, doi:10.1080/03069885.2019.1625026.
Note that the title of the article is in 'single quotation marks' and sentence case. The title of the journal is in italics - it has capitals on all the major words because you treat journal titles like company names.