A new metadata scheme can be created by using the function
scheme_make. This function will create a package to add
functionality to the currently used scheme as a package which will depend on
scheme_active(). This function uses the function package.skeleton()
from the utils package to create a new directory for the new metadata
scheme, and adds a function aaa.R which loads the current package
whenever the new package is loaded as well as some fields to the
DESCRIPTION file.
For a documentation of the workflow to create a new scheme, see the vignette
Howto Create a new scheme.