[dragonwriter]

> In the context of RPC, is it still impractical?

If you are defining a bespoke RPC protocol that incidentally uses some parts of HTTP without much concern about the spec but only concern with what existing infrastructure will do with requests, you have…lots of freedom to design things however you want.

OTOH, a lot of work has gone into handling almost every conceivable aspect of information interchange, within a REST style (because REST was both derived from the architecture of the Web and used in updating HTTP for HTTP/1.1) in the HTTP standards (there are some gaps still, like that addressed by the draft QUERY [0] method), why reinvent the wheel, unless you are specifically dealing with use cases squarely within the gaps?

[0] https://www.ietf.org/archive/id/draft-ietf-httpbis-safe-meth...