transaction and request ID clarifications

OpenRTB v3.0 FINAL.md

@@ -431,7 +431,7 @@ NOTE:  Attributes `ds`, `dsmap`, `cert`, and `digest` support digitally signed b
   <tr>
     <td><code>tid</code></td>
     <td>string; recommended</td>
-    <td>Transaction ID that must be common across all participants throughout the entire supply chain of this transaction.  This also applies across all participating exchanges in a header bidding or similar publisher-centric broadcast scenario.</td>
+    <td>Transaction ID, generated by the publisher or agent originating an ad request for the end user, that must be common across all participants in this bid request (e.g., all exchanges participating in a header bidding or similar publisher-centric broadcast scenario). It should not be assumed that this ID uniquely identifies 1 biddable impression opportunity, unless that's all that exists on the bid request. Any podded audio/video bid request or multi-impression bid request may reflect multiple concurrent biddable impression opportunities. To uniquely identify those, consider using <a href="https://github.com/InteractiveAdvertisingBureau/openrtb/blob/master/extensions/community_extensions/per-imp-tids.md">per-impression transaction IDs</a>.</td>
   </tr>
   <tr>
     <td><code>ts</code></td>

supplychainobject.md

@@ -85,7 +85,7 @@ This object is associated with a SupplyChain object as an array of nodes. These
   <tr>
    <td>rid</td>
    <td>String; optional</td>
-   <td>The OpenRTB RequestId of the request as issued by this seller.</td>
+   <td>The OpenRTB RequestId of the bid request as issued by the advertising system associated with this Supply Chain Node.</td>
   </tr>
   <tr>
    <td>name</td>