diff --git a/spec/spec.md b/spec/spec.md
index 2d84c35..d85364c 100644
--- a/spec/spec.md
+++ b/spec/spec.md
@@ -184,7 +184,7 @@ Issuer/Issuee
 
 [[def: Attribute]]
 
-~ a property of an entity that is inherent or assigned to the entity.
+~ a top-level field map within an ACDC that provides a property of an entity that is inherent or assigned to the entity.
  
 [[def: Targeted ACDC]]
 
@@ -196,21 +196,32 @@ Issuer/Issuee
 
 [[def: Operator]]
 
-~
+~ an optional field map in the Edge section that enables expression of the edge logic on edge subgraph as either a unary operator on the edge itself or an m-ary operator on the edge-group.
 
 [[def: Weight]]
 
+~ an optional field map in the Edge section that provides edge weight property that enables directed weighted edges and operators that use weights.
+
+[[def: Permissioned correlation]]
+
 ~
 
+[[def: Percolated discovery]]
+
+~ a discovery mechanism
+
+[[def: Rules]]
+
+~ a top-level field map within an ACDC that provides a legal language as a Ricardian Contract [@RC], which is both human and machine-readable and referenceable by a cryptographic digest. 
+
+[[def: Edge]]
+
+~ a top-level field map within an ACDC that provides edges that connect to other ACDCs, forming a labeled property graph (LPG).
 
+[[def: Schema]]
 
-TBD
+~ the SAID of a JSON schema that is used to issue and verify an ACDC.
 
-Permissioned correlation
-Percolated discovery
-Rules 
-Edge
-Schema
 
 ::: issue
 https://github.com/trustoverip/tswg-acdc-specification/issues/16