A frontmatter may contain fields Quartz does not know. They do no harm, and they are useful: Obsidian can search and sort by them, a base can filter by them, and the plugin Note properties shows them in a table under the title — as at the top of this page.
What this page carries
It has more frontmatter than is displayed. The template lists thirteen fields on the plugin under
includedProperties: description, tags and section, which every page can have, plus the five
demo fields — number, truthy, falsy, list, empty — and the same five once more with
German names, because the German version of this page calls them so. A field a page does not have
gets no row; the table above therefore counts eight.
The five demo fields exist so that every kind of value appears once: a number, a yes, a no, a list, an empty field. How the table shows each of them differently stands in The property table.
aliases and translationKey are not displayed: both are machinery and would stand on almost
every page.
section — this site’s own field
Every page here carries section with the name of its chapter. Quartz does not know the field. It
appears in the property table, the base All pages groups by it,
and a layout box could insert it as the placeholder {{frontmatter.section}}.
Showing all fields
Whoever wants to see all fields sets the option includeAll to true in QuartzControl under
Plugins → Note properties. Then aliases and translation keys appear as well.
How to write fields and which data types there are: 2.11 – Properties.