diff --git a/README.md b/README.md
index c0f3d3d..4505510 100644
--- a/README.md
+++ b/README.md
@@ -29,13 +29,12 @@ interop and upgrades.  To work with Harmony, services must:
 supported way to receive messages, though HTTP is likely to follow.  `harmony.cli`
 provides helpers for setting up CLI parsing while being unobtrusive to non-Harmony
 CLIs that may also need to exist.
-2. Extend `harmony.BaseHarmonyAdapter` and implement the `#invoke` to
-adapt the incoming Harmony message to a service call and adapt the service
-result to call to one of the adapter's `#completed_with_*` methods. The adapter
-class provides helper methods for retrieving data, staging results, and cleaning
-up temporary files, though these can be overridden or ignored if a service
-needs different behavior, e.g. if it operates on data in situ and does not
-want to download the remote file.
+2. Extend `harmony.BaseHarmonyAdapter` and either override `#invoke` to process
+the message or override `#process_item` to process each individual STAC item
+provided in the input STAC catalog. The adapter class provides helper methods
+for retrieving data, staging results, and cleaning up temporary files, though
+these can be overridden or ignored if a service needs different behavior, e.g.
+if it operates on data in situ and does not want to download the remote file.
 
 A full example of these two requirements with use of helpers can be found in
 [example/example_service.py](example/example_service.py). Also see
diff --git a/harmony_service_lib/message.py b/harmony_service_lib/message.py
index a1e308f..b66720f 100644
--- a/harmony_service_lib/message.py
+++ b/harmony_service_lib/message.py
@@ -582,9 +582,7 @@ class Message(JsonObject):
     version : string
         The semantic version of the Harmony message contained in the provided JSON
     callback : string
-        The URL that services must POST to when their execution is complete.  Services
-        should use the `completed_with_*` methods of a Harmony Adapter to perform
-        callbacks to ensure compatibility, rather than directly using this URL
+        (Deprecated) The URL that services must POST to when their execution is complete.
     stagingLocation : string
         An object store (S3) URL prefix under which services may elect to put their output.
         Services must have write access to the Harmony staging bucket for the deployed
diff --git a/tests/test_cli.py b/tests/test_cli.py
index 10b4a20..6545b02 100644
--- a/tests/test_cli.py
+++ b/tests/test_cli.py
@@ -28,9 +28,6 @@ def __init__(self, message, catalog=None):
     def invoke(self):
         return (self.message, self.result_catalog)
 
-    def completed_with_error(self, error):
-        MockAdapter.errors.append(error)
-
     def cleanup(self):
         MockAdapter.cleaned_up.append(True)