PRISMA-P: a checklist of items you should include in your protocol.
IOM Standard 2.6 for Systematic Reviews Protocols a short checklist and explanation of protocol items
MECIR Standards for Protocols: standards that Cochrane reviews must adhere to. Even if you're not doing a Cochrane review, there is helpful guidance in the section on "Developing the Protocol for the Review."
Developing a protocol before you begin will help you plan how you'll conduct your systematic review. Many of the elements in the protocol will also be used in your final article. Your protocol should should specify: