No one may perform any checkins, checkouts, or branches off a codeline
without approval from the codeline-owner; or else no one at a remote
site may do anything to a codeline at the master-site, without approval
from the master-site.
Lock (freeze) a codeline against all further development while it is
being prepared for a release. Then, either decommission the codeline
(leaving it locked), or else unlock the codeline after release efforts
have completed to resume development.
Sometime multiple platform lines
will necessitate a mainline for each major platform, especially when the
different platforms cannot be meaningfully integrated into a single
Similarly, if multiple
are used for a major release-line,
then a mainline may be used for each such major release, component, or
subproject (perhaps feeding back up to a system-wide integration
Instead of freezing the codeline during release engineering activities,
a separate line is created for release integration and engineering
while allowing other development to continue taking place on the
Cyclic promotion lines are staged integration lines where changes must
progress from the development line through the entire promotion cycle
before being merged back into the development line. Thus changes take
a cyclic path to end up back in the codeline from which they were
Define change migration relationships between codelines (e.g. fixes
from release 1.1 need to migrate to release 2.0) and ensure that
changes originating from the same codeline are propagated in the same
order in which they were originally completed and merged.
When version controlling local changes to third party code, user separate
codeline to represent the vendor's development and your own local development
and merge updates from the vendor-line into the local-line.
Internal users of a centralized repository perform changes and integration
on a restricted-access line reserved for internal-use only. Geographically
dispersed users perform development on a separate external-line that
is periodically synchronized with the internal-line.