Update substream text

capabilities/README.md

@@ -254,14 +254,14 @@ It MAY be used in place of the file with the same name in the AMWA BCP-004-01 sp
 ## Substream Constraints
 
 Mux Senders create IS-04 Flow objects for each subflow included in the mux Flow.
-The mux Flow links to each subflow object using the `parents` construct described in [AMWA IS-04](https://specs.amwa.tv/is-04/)
+The mux Flow links to each subflow object using the IS-04 [`parents`](https://specs.amwa.tv/is-04/latest/docs/Data_Model_-_Identifier_Mapping.html#source-and-flow-representation) attribute.
 
 ### Substreams
 - **Name:** `urn:x-nmos:substreams`
 - **Description:** Identifies any per substream constraints.
 - **Specification:** per AMWA BCP-004-01
-  - **Type:** object (as per [AMWA BCP-004-01](https://specs.amwa.tv/bcp-004-01/))
-  - **Target:** mux Sender subflows and their associated attributes sub-targeted by individual Substream Parameter Constraints
+  - **Type:** array of objects (as per [AMWA BCP-004-01](https://specs.amwa.tv/bcp-004-01/))
+  - **Target:** mux Sender subflows and their associated attributes targeted by individual Substream Parameter Constraints
 - **Applicability:** AMWA IS-04
 
 [RFC-4566]: https://tools.ietf.org/html/rfc4566 "SDP: Session Description Protocol"