Where are Vagrant symbols (special values) documented?

Question

Both in the documentations of Vagrantfile and in different Vagrantfile files we find symbols like the following:

:id, :ssl, :plaintext, :negotiate :auto, :linux, :windows.

Where are those symbols (special values) documented?

What is the right name for them? Symbols, special variables, special values ...?

Answer 1

As pointed out by @Menelaos the documentation is in Vagrant GitHub repository in the MDX-files.

A grep of the pattern "\`:[^\` ]*\`" gets all the "special symbols" mentioned in the MDX-files:

$ cd /path/to/vagrant_repo
$ find . -name "*.mdx" -type f -exec grep -iPo "\`:[^\` ]*\`" {} \; | sort | uniq
`:accept_new_or_local_tunnel`
`:accept_new`
`:action`
`:all`
`:always`
`:auto_correct`
`:auto`
`:bootstrap`
`:bridge`
`:bridged`
`:chef_solo`
`:command`
`:continue`
`:datadir`
`:default`
`:detect`
`:disable_warning`
`:disk`
`:dvd.`
`:dvd`
`:each`
`:ecdsa256`
`:ecdsa384`
`:ecdsa521`
`:ed25519`
`:force`
`:halt`
`:hook`
`:id`
`:ip`
`:linux`
`:machine`
`:negotiate`
`:never`
`:pip_args_only`
`:pip`
`:plaintext`
`:provider`
`:rsa`
`:shell`
`:single_run`
`:ssl`
`:type`
`:ui`
`:up`
`:user_data`
`:windows`
`:winrm`

Or a complete grep of all "special symbols" to find all places in the documentation where a "special symbol" is used:

$ find . -name "*.mdx" -type f -exec grep -iPo "\`:[^\` ]*\`" {} \; \
    | sort \
    | uniq \
    | xargs -Ixxx find . -name "*.mdx" -exec grep --color=always -Hne xxx {} \;

./website/content/docs/vagrantfile/ssh_settings.mdx:155:  default value is `:never`. The other options are `:accept_new_or_local_tunnel`,
./website/content/docs/vagrantfile/ssh_settings.mdx:156:  `:accept_new`, or `:always`, which each refer to one of
./website/content/docs/triggers/configuration.mdx:102:  - `:action` - Action triggers run before or after a Vagrant action
./website/content/docs/provisioning/basic_usage.mdx:27:  values are `:each` or `:all`, which makes the provisioner run before each and
...
./website/content/docs/cloud-init/configuration.mdx:49:config.vm.cloud_init :user_data, content_type: "text/cloud-config", path: "config.cfg"
./website/content/docs/cloud-init/configuration.mdx:51:config.vm.cloud_init :user_data do |cloud_init|
./website/content/docs/cloud-init/configuration.mdx:57:However, this is not a requirement. Leaving off `type` will default to `:user_data`.
./website/content/docs/cloud-init/configuration.mdx:60:  cloud-init config. Currently, the only supported `type` is `:user_data`. If a type
./website/content/docs/cloud-init/configuration.mdx:61:  is not defined, it will default to `:user_data`.
./website/content/docs/vagrantfile/machine_settings.mdx:137:  proper distro. However, this should be changed to `:windows` for Windows guests.
./website/content/docs/vagrantfile/winrm_settings.mdx:18:These settings are only used if you've set your communicator type to `:winrm`.