Unpermissioned correlation & Percolated discovery

Signed-off-by: Nuttawut Kongsuwan <[email protected]>

spec/spec.md

@@ -202,13 +202,13 @@ Issuer/Issuee
 
 ~ 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: Unpermissioned correlation]]
 
-~
+~ a correlation established between two or more disclosed ACDCs whereby the discloser of the ACDCs does not permit the disclosee to establish such a correlation.
 
 [[def: Percolated discovery]]
 
-~ a discovery mechanism
+~ a discovery mechanism for information associated with an AID or a SAID, which is based on Invasion Percolation Theory. Once an entity has discovered such information, it may in turn share what it discovers with other entities. Since the information so discovered is end-verifiable, the percolation mechanism and percolating intermediaries do not need to be trusted.
 
 [[def: Rules]]
 
@@ -222,7 +222,6 @@ Issuer/Issuee
 
 ~ the SAID of a JSON schema that is used to issue and verify an ACDC.
 
-
 ::: issue
 https://github.com/trustoverip/tswg-acdc-specification/issues/16
 :::