Which services is it safe to parent objects to?

Some services like workspace or Lighting or others are saved when you save to Roblox. Others such as DataStoreService are saved when you save to a file but not when you save to Roblox. I wonder if there is a way to know which services will retain the objects parented to them, i.e., which services are always serialized? For example, is CollectionService one of them or not?