[Bitcoin-development] [BIP draft] Motivation and deployment of consensus rules changes ([soft/hard]forks)

[Jorge Timón]

This is an attempt to unify views on why and how hardforks can be
deployed. I would like to turn this into an informational BIP later
after gathering some feedback.

Please, do not discuss block size issues here: there's plenty of
threads to do so. The scope of this one is only hardforks and
softforks in a more abstract way. Sometimes block size changes are
used as examples because no other example came to mind
(non-blocksize-related examples for the same cases [or others] are
a user should be just ignored. But what if the welcomed), and
if we go into too much detail they stop being useful as examples. So
please, try to avoid going into too much detail about the concrete
examples when possible.

https://github.com/jtimon/bips/blob/bip-forks/bip-forks.org

Please, feel free to make suggestions or bike-shed some of the terms.