YAML stands for “YAML Ain’t Markup Language.” More information can be found at the YAML website.

SilverBullet uses YAML in various contexts, specifically Frontmatter and Space Config

Internal links

Many string values can be written directly in YAML without any quoting, like:
property: value


However when you want to reference a page or command you will need to quote the full link:
some page: "[[Pages]]"
list of pages:
  - "[[Pages]]"
  - "[[Links]]"


This is because the square brackets used in the internal link format have a meaning in YAML as well. So an unquoted link is parsed as list inside a list:
some page: [[Pages]]
equivalent yaml: [
    [ "Pages" ]
]