What may be included in the Sprint Backlog?

According to the Scrum Guide, the Sprint Backlog may include any items that are a decomposition of the selected Product Backlog items, such as user stories, tasks, use cases, tests, or others. The Sprint Backlog is the Developers’ plan for the Sprint, and it contains all the work that they forecast they can do to achieve the Sprint Goal and create a “Done” Increment. The other options are not valid, as they are either too specific (such as user stories or tasks) or too vague (such as tests).