darwin calendar server client tool

Cyrus Daboo posted a set of tools for working with CalDAV/Darwin Calendar Server. It's got a learning curve... but some helpful tips:

• in the client tool, ? brings up a list of commands.
• in pyclient, the syntax for help on one of those commands is "help [command]"
• when inside a command's interactive mode, 'help' lists options

So, for instance, say you want to edit the ACL on a principal's calendar, but you don't know how.

/ > ? acl - Manage the access privileges of a directory or file.
cat - Display contents of a file or directory.
cd - Change working directory.
exit - Terminates this session.
help - Displays help about a command.
history - Displays the history of all commands used in this session.
logging - Changes the current state of HTTP logging.
ls - List the contents of a directory.
principal - Displays the current server login id.
props - List the properties of a directory or file.
proxies - Displays the delegates for the chosen user.
quit - Terminates this session.
server - Displays the current server.
whoami - Displays the current server login id.

As you can see, using ? pointed me to the acl command. Now, to use it:

/ > help acl
Command: acl
Description: Manage the access privileges of a directory or file.
Usage: acl [OPTIONS] [PATH]
PATH is a relative or absolute path.

Options:
-i interactive mode for adding, changing and deleting ACLs.
if not present, existing ACLs will be printed.

So, I just do as follows:

/ > acl -i /calendars/users/tack/calendar
Entering ACL edit mode on resource: /calendars/users/tack/calendar/
ACL >

but what do I do from here?

ACL > help
add - Add ACL to existing resource.
change - Change ACL on existing resource.
exit - Terminates this session.
help - Displays help about a command.
list - List current ACLs on existing resource.
logging - Changes the current state of HTTP logging.
quit - Terminates this session.
remove - Remove ACL on existing resource.

Help tells me how to work on the ACL's for this.