All users except collaborators can edit projects and can add them to an archived location.
If you no longer regularly use a project but don't want to delete it, creating an archive is a great solution. You can create a personal archive in your Personal space or team archives in team spaces.
Navigate to the relevant space and create a folder named Archive.
Organization in the left-hand navigation panel is alphabetical, so if you want your archive at the bottom of a list consider naming it zArchive.
Add subfolders to your archive folder if you want to further organize your archive, i.e., you could create subfolders for different years or individual clients.
When a project needs to be archived you can simply move that item to the archive folder. If you ever need to take data out of the archive, you can drag and drop it in the left-hand navigation panel out of the archive back into the space that archive belongs to.