Those are not restrictions to REST, since REST doesn't make any specific claims about how to use things like filtering, sorting etc.
Google created GData2 as an extension to AtomPub format, which only specifies a common envelope for resources (Atom Syndication Format) and how to talk about collections of resources (AtomPub itself).
There is another notable extension to AtomPub format from Microsoft called OData.
Google created GData2 as an extension to AtomPub format, which only specifies a common envelope for resources (Atom Syndication Format) and how to talk about collections of resources (AtomPub itself).
There is another notable extension to AtomPub format from Microsoft called OData.