complement
collections.Complement (alias complement) gives the elements of a collection that are not in any of the others.
Syntax
COLLECTION | complement COLLECTION [COLLECTION]...
Example:
{{ $pages := .Site.RegularPages | first 50 }}
{{ $news := where $pages "Type" "news" | first 5 }}
{{ $blog := where $pages "Type" "blog" | first 5 }}
{{ $other := $pages | complement $news $blog | first 10 }}
The above is an imaginary use case for the home page where you want to display different page listings in sections/boxes on different places on the page: 5 from news, 5 from the blog and then 10 of the pages not shown in the other listings, to complement them.