To repeat, it’s best to use @file to create external files if at all possible. The next series of slides will show you how to create external files with @file trees.
To create a new external file, create an @file node giving the path to the external file. This path can be a full, absolute path, but usually it is more convenient to use a relative path. All relative paths in @<file> nodes are relative to Leo’s load directory, the directory containing the .leo file for the present outline. In most cases, we can ignore the path prefix entirely.