Clarify "between major version changes"
This was diversely interpreted as "compatibility in the period between
two major version changes" (as intended) or "compatibility between two
versions whose major version is different" (unintended).
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/BRANCHES.md b/BRANCHES.md
index df30ae1..b9926ac 100644
--- a/BRANCHES.md
+++ b/BRANCHES.md
@@ -16,9 +16,10 @@
these only get bug fixes and security fixes.
We use [Semantic Versioning](https://semver.org/). In particular, we maintain
-API compatibility in the `master` branch between major version changes. We
-also maintain ABI compatibility within LTS branches; see the next section for
-details.
+API compatibility in the `master` branch across minor version changes (e.g.
+the API of 3.(x+1) is backward compatible with 3.x). We only break API
+compatibility on major version changes (e.g. from 3.x to 4.0). We also maintain
+ABI compatibility within LTS branches; see the next section for details.
## Backwards Compatibility