1.11. Collections
Content management isn't just about adding, editing, and approving content. It's also about helping users understand the connection between pieces of content.
The inclusion of text and metadata has allowed CMS products to become more flexible and have less rigid folder schemes. Instead of creating a process so you can remember where you saved specific files or documents, you can now store a detailed search as a Collection. Reduce your chaos. Have your content right at hand.

Plone takes this idea and makes it much more powerful and easy-to-use. Want to show all news items created by the Marketing department in the past week? Need an automatically updated list of all the files added to your project as it progresses? Collections to the rescue!
New in Plone 3.0: Collections (formerly known as Smart Folders) can now also store explicit references in addition to the stored search. This is very handy when you want to create a list of reports, with a document at the top which gives instructions on how to read them, for instance.
Creating Collections is a straightforward task, and the creator can even decide how the results should be listed visually — all without writing any HTML or a single line of code.
Collections are also RSS-enabled out-of-the-box, so a simple blog can be created with just a few clicks!

How are the references added to the collection?