That link does not work, however I did find documentation on Entries
here
. FYI: in the admin area of Business 1.6.0 the help button for Entries shows "Documentation currently not available : entry-listing". For anyone else who is wondering what this feature does, the extensive documentation states this feature is "useful for example if you are building a website for an event, and you have several options available with different prices and you want your users to be able to enter several persons to the event in one order."