> I'm mostly wondering if it is worth future-proofing for new transports. It sounds like we can have a consensus on leaving the upper 4 bits of the speed fields reserved, but leave the details of implementation for the future? It seems reasonable, although I think the reality is that any future transport is not going to be a true serial link, but some kind of serial emulation layer. For those the speed really only matters to tell editors and the like not to bother being clever. I mean - what is the baud rate of a pty ? Alan