It's new thing time! The CodePen team brings you collections. Collections are groups of Pens that you create. You can add any Pen that you can see to them. For example, here's a collection I created that I named Form Designs:
Collections allow you to bring together Pens into a group for any reason you can think of. Perhaps they are different examples of a particular design pattern. Perhaps they share a same color scheme. Or perhaps you wish to collect bits and pieces that you would like to reference for a new project of your own.
Creating Collections and Adding Pens
You do this from any Pen's editor view. Click the "+ Add to Collection" button in the footer. From here you can select an existing collection to add to, or create a new collection and add this Pen immediately.
Deleting Collections and Removing Pens
You can delete a collection from your profile page, under the collections tab where all your collections are shown.
You can remove a Pen from a collection from that Pens context menu in the collection itself.
Removing a Pen from a collection doesn't delete the Pen, it's just not in that collection anymore. Deleting a Pen will remove it from a collection also.
Also note that Private Pens (of your own) may be added to collections, but nobody but you will be able to see them until you choose to make them public.
Isn't this just tagging?
Collections share some characteristics with tagging (they are groups of Pens) but they are, by design, fundamentally different.
Only you can tag your Pens. And you can't tag other people's Pens. So tags are groups of related Pens, but they are self-organized by the CodePen community automatically. There is no curation of what a tag group contains.
Collections are the opposite in that you can add any Pen to a collection and anybody else can add your Pens to their collections. They are pure curation.
This is just the beginning for collections. We kept it simple so you can help us shape it's future. We've thought of things like making collections themselves heart-able and having collaborators on collections. But we want to know what you think and what you'd like to see! Let us know in the comments.