diff --git a/agora pkg chapter.md b/agora pkg chapter.md
index c31dd616f..808b2ec21 100644
--- a/agora pkg chapter.md	
+++ b/agora pkg chapter.md	
@@ -69,7 +69,8 @@ The Agora can be defined in a nutshell as a subset of the [[internet]][^web] use
 
 - [[Agora]]: a [[protocol]], a [[platform]], a [[commons]].
 - [[Graph]]: the heart of the Agora. A distributed [[knowledge graph]] in particular, both explicitly and implicitly containing a variety of social graphs.
-- [[Node]]: a vertex in the knowledge graph. Maps to an [[entity]] description encoded in a [[wikilink]] or #hashtag.
+- [[Node]]: a vertex in the knowledge graph. Maps to an [[entity]] description encoded in a [[wikilink]] or #hashtag. Maps to a mental [[context]] in an Agora user.
+- [[Subnode]]: a resource contributed by a user which the Agora will provision when queried for a variety of [[Node]] contexts. A node is a collection of subnodes.
 - [[Link]]: an annotated edge in the knowledge graph. Maps to an [[entity]] description encoded in [[wikilinks]] or #hashtags.
 
 # Principles