“Defaults files” are a convenient tool to store, group, and combine related command line options.
E.g., instead of typing

pandoc --pdf-engine=xelatex -V csquotes

one could create a file `pdf.yaml` with

pdf-engine: xelatex
variables: {csquotes: true}

and use it with

pandoc -d pdf.yaml

https://pandoc.org/MANUAL#defaults-files

#pandoc #cli #yaml