Clarified semantics of "group name" and "node name".

Author: marco-tiloca-sics

draft-ietf-ace-key-groupcomm.md

@@ -39,6 +39,7 @@ author:
 
 normative:
   RFC2119:
+  RFC3629:
   RFC6749:
   RFC6838:
   RFC8126:
@@ -156,13 +157,13 @@ A principal interested to participate in group communication as well as already
 
 Furthermore, this document uses "names" or "identifiers" for groups and nodes. Their different meanings are summarized below.
 
-* Group name: the invariant once established identifier of a group. It is used in the interactions between Client, AS, and RS to identify a group. A group name is always unique among the group names of the existing groups under the same KDC.
+* Group name: the identifier of a group, as a text string encoded as UTF-8 {{RFC3629}}. Once established, it is invariant. It is used in the interactions between Client, AS, and RS to identify a group. A group name is always unique among the group names of the existing groups under the same KDC.
 
 * GROUPNAME: the invariant once established text string used in URIs. GROUPNAME uniquely maps to the group name of a group, although they do not necessarily coincide.
 
 * Group identifier: the identifier of the group keying material used in a group. Unlike group name and GROUPNAME, this identifier changes over time, when the group keying material is updated.
 
-* Node name: the invariant once established identifier of a node. It is used in the interactions between Client and RS, as well as to identify a member of a group. Within the same group, a node name is always unique among the node names of all the current members of that group.
+* Node name: the identifier of a node, as a text string encoded as UTF-8 {{RFC3629}}. Once established, it is invariant. It is used in the interactions between Client and RS, as well as to identify a member of a group. Within the same group, a node name is always unique among the node names of all the current members of that group.
 
 * NODENAME: the invariant once established text string used in URIs to identify a member of a group. Its value coincides with the node name of the associated group member.