The required fields must be in your singlefeed in order for it to be accepted. However, SingleFeed also supports over 50 optional fields. Although you do not have to fill these out, we recommend that you fill in as many as you can to make your feed as complete as possible. The more data you provide, the greater potential your shopping engine campaigns have to perform well. Please review this document for a complete list of required and optional fields.

https://www.singlefeed.com/pdf/Product_Import_Instructions.pdf