Clarify hierarchy
@@ -14,12 +14,13 @@ Repository Delta Protocol (RRDP), which relies on HTTPS. RRDP was designed to be
the successor to rsync in the RPKI. As almost all RPKI repositories currently
support both protocols, Routinator will prefer RRDP if available.
-When traversing the RPKI hierarchy, starting at the trust anchors of the
-Regional Internet Registries (RIRs), Routinator will find several pointers to
-child publication points, such as the ones operated by National Internet
-Registries (NIRs), Local Internet Registries (LIRs) and organisations running
-delegated RPKI. Each pointer explicitly states if RRDP is offered in addition to
-rsync.
+In the RPKI, the certificate hierarchy follows the same structure as the
+Internet number resource allocation hierarchy. Routinator starts traversing the
+tree by connecting to the trust anchors of the Regional Internet Registries
+(RIRs). Along the way Routinator will find several pointers to child publication
+points, such as the ones operated by National Internet Registries (NIRs), Local
+Internet Registries (LIRs) and organisations running delegated RPKI. Each
+pointer explicitly states if RRDP is offered in addition to rsync.
.. figure:: img/ca-structure.svg
:align: center
