Optional features tend to be broken in practice. So HTTP/2 is trying to have far fewer of them so that implementations will be more robust.
Chunked requests and pipelines are good examples. They are rarely used but absolutely supported by the spec. But because they are rarely used they break a lot in practice and are not realistically deployable on Internet scale.
Chunked requests and pipelines are good examples. They are rarely used but absolutely supported by the spec. But because they are rarely used they break a lot in practice and are not realistically deployable on Internet scale.