cschem - use cases

The "back annotation"

any <-> sch flow
in a later phase of the project, in a 3rd party software (e.g. PCB layout tool, simulation software) some change is made that has to be carried back to the schematics

net change: multiple ways a network connection can be specified
net change: hierarchy; what if a schematics is used in 4 instances and there's a change only in one instance?
attribute change: attributes may be calculated by plugins (source shall be changed)