message: Document LTS PR label policy
diff: @@ -25,3 +25,16 @@ Create a dev release
  ---------------------
  1. Tag the head of ``main`` as ``ccf-N+1.0.0-devX+1``, where ``N`` is the latest LTS, and ``X`` the latest dev release.
  +
  +Labelling LTS PRs
  +-----------------
  +
  +To keep track of which changes should be merged to LTS branches and then confirm them before cutting LTS releases, the following policy should be used:
  +
  + 1. A PR targetting ``main`` which contains changes that should also reach the LTS should be labelled in GitHub with ``lts-candidate``
  + 2. Where possible ``lts-candidate`` PRs should contain the minimal set of changes with no dependencies on earlier PRs, so they can be more easily cherry-picked
  + 3. A PR targetting an LTS branch (``release/N.x``) should be labelled in Github with ``lts``, so it can be easily found with a filter
  + 4. A PR targetting an LTS branch which is constructed primarily of a cherry-pick from ``main`` should be named consistently as ``Cherry-pick #<PR_ID> to N.x LTS``, so it can be easily correlated with the corresponding ``lts-candidate`` PR. If an LTS PR contains commits from multiple PRs to ``main``, each should be mentioned in the PR title, eg ``Port <foo> to N.x LTS (#PR1_ID, #PR2_ID, ...)```
  + 5. Once a corresponding cherry-pick has been merged to the LTS branch, the ``lts-candidate`` label can be removed from the original PR
  +
  +Before creating an LTS release, the releaser should do a scan of PRs and ensure that there are none with ``lts-candidate`` label. If any exist, they should be merged to the LTS branch before releasing, and those candidate labels removed.
  