ezpm.php documentation page is missing for specific eZPublish versions like 4.7.

Besides, the existent documentation page is incomplete with no examples and no options and parameters. Somebody added a comment with a link to eZPedia:
http://www.ezpedia.org/en/ez/command_line_package_manager

Specifically, the script documentation should explain for what the commands should be used:

1. How to create a new package
2. How to add a single node and a subtree to the created package
3. How to download the package
4. How to Import a package file to eZ Publish
5. Hot to install the package's content to eZ Publish

Usage examples

^{based on local testings}

Create a new package and add a subtree to it

/usr/bin/php ezpm.php create test_package "Test Package Creation"
/usr/bin/php ezpm.php add test_package ezcontentobject --exclude-templates --subtree=1 --exclude-classes --siteaccess=eng "your_path_to_content/*"

Download the created package

/usr/bin/php ezpm.php export test_package --output -d /your/folder

Import and install the package

php ezpm.php --debug import test_package-1.0-1.ezpkg
php ezpm.php --debug install test_package