Avoiding duplicate manifests entries and cleaning the README.
diff --git a/README b/README
index d78be8f..5cd89a4 100644
--- a/README
+++ b/README
@@ -1,9 +1,7 @@
-=========
-MANIFESTS
-=========
+# Manifests
The files in this repository are referred to as "manifests" and
-are used by the veyron tool for multi-repository management. Each
+are used by the v23 tool for multi-repository management. Each
manifest describes a set of projects and each project consist of a
remote repository, a local path, and other optional attributes.
@@ -13,3 +11,12 @@
veyron tool by default. Format of existing manifest files should not
be changed as old versions of the veyron tool would not be able to
parse them.
+
+To add a project to an existing Vanadium universe, one should add
+it to relevant manifest for all versions that are still supported,
+following the format of the respective versions.
+
+Further, the set of projects that form a Vanadium universe should be
+closed under transitive closure with respect to dependencies. In other
+words, if a project A depends on a project B, then project A should
+only be included in manifests that include project B as well.
