diff --git a/archivebox/actors/actor.py b/archivebox/actors/actor.py
index e31b55f1..b5a82724 100644
--- a/archivebox/actors/actor.py
+++ b/archivebox/actors/actor.py
@@ -32,7 +32,7 @@ class ActorQueueIsEmpty(Exception):
 
 CPU_COUNT = cpu_count()
 DEFAULT_MAX_TICK_TIME = 60
-DEFAULT_MAX_CONCURRENT_ACTORS = min(max(2, int(CPU_COUNT * 0.6)), 8)   # 2 < 60% * num available cpu cores < 8
+DEFAULT_MAX_CONCURRENT_ACTORS = min(max(2, int(CPU_COUNT * 0.6)), 8)   # 2 < (60% * num available cpu cores) < 8
 
 limit = lambda n, max: min(n, max)
 
@@ -569,3 +569,4 @@ def compile_sql_update(queryset: QuerySet, update_kwargs: dict[str, Any], filter
     # e.g. UPDATE core_archiveresult SET status='%s', retry_at='%s' WHERE status NOT IN (%s, %s, %s) AND retry_at <= %s
     update_sql, update_params = query.get_compiler(queryset.db).as_sql()
     return update_sql, update_params
+
diff --git a/archivebox/core/actors.py b/archivebox/core/actors.py
index 44b6d31d..18281336 100644
--- a/archivebox/core/actors.py
+++ b/archivebox/core/actors.py
@@ -10,12 +10,16 @@ from actors.actor import ActorType
 
 
 class SnapshotActor(ActorType[Snapshot]):
+    """
+    The primary actor for progressing Snapshot objects
+    through their lifecycle using the SnapshotMachine.
+    """
     Model = Snapshot
     StateMachineClass = SnapshotMachine
     
-    ACTIVE_STATE: ClassVar[State] = SnapshotMachine.started
-    FINAL_STATES: ClassVar[list[State]] = SnapshotMachine.final_states
-    STATE_FIELD_NAME: ClassVar[str] = SnapshotMachine.state_field_name
+    ACTIVE_STATE: ClassVar[State] = SnapshotMachine.started                    # 'started'
+    FINAL_STATES: ClassVar[list[State]] = SnapshotMachine.final_states         # ['sealed']
+    STATE_FIELD_NAME: ClassVar[str] = SnapshotMachine.state_field_name         # status
     
     MAX_CONCURRENT_ACTORS: ClassVar[int] = 3
     MAX_TICK_TIME: ClassVar[int] = 10
@@ -24,12 +28,16 @@ class SnapshotActor(ActorType[Snapshot]):
 
 
 class ArchiveResultActor(ActorType[ArchiveResult]):
+    """
+    The primary actor for progressing ArchiveResult objects
+    through their lifecycle using the ArchiveResultMachine.
+    """
     Model = ArchiveResult
     StateMachineClass = ArchiveResultMachine
     
-    ACTIVE_STATE: ClassVar[State] = ArchiveResultMachine.started
-    FINAL_STATES: ClassVar[list[State]] = ArchiveResultMachine.final_states
-    STATE_FIELD_NAME: ClassVar[str] = ArchiveResultMachine.state_field_name
+    ACTIVE_STATE: ClassVar[State] = ArchiveResultMachine.started                # 'started'
+    FINAL_STATES: ClassVar[list[State]] = ArchiveResultMachine.final_states     # ['succeeded', 'failed', 'skipped']
+    STATE_FIELD_NAME: ClassVar[str] = ArchiveResultMachine.state_field_name     # status
     
     MAX_CONCURRENT_ACTORS: ClassVar[int] = 6
     MAX_TICK_TIME: ClassVar[int] = 60
diff --git a/archivebox/core/statemachines.py b/archivebox/core/statemachines.py
index 9dc2ddb3..88a48b82 100644
--- a/archivebox/core/statemachines.py
+++ b/archivebox/core/statemachines.py
@@ -11,7 +11,11 @@ from core.models import Snapshot, ArchiveResult
 
 
 class SnapshotMachine(StateMachine, strict_states=True):
-    """State machine for managing Snapshot lifecycle."""
+    """
+    State machine for managing Snapshot lifecycle.
+    
+    https://github.com/ArchiveBox/ArchiveBox/wiki/ArchiveBox-Architecture-Diagrams
+    """
     
     model: Snapshot
     
@@ -47,8 +51,13 @@ class SnapshotMachine(StateMachine, strict_states=True):
         self.snapshot.retry_at = None
         self.snapshot.save()
 
+
 class ArchiveResultMachine(StateMachine, strict_states=True):
-    """State machine for managing ArchiveResult lifecycle."""
+    """
+    State machine for managing ArchiveResult lifecycle.
+    
+    https://github.com/ArchiveBox/ArchiveBox/wiki/ArchiveBox-Architecture-Diagrams
+    """
     
     model: ArchiveResult
     
diff --git a/archivebox/pkgs/abx-plugin-singlefile/abx_plugin_singlefile/models.py b/archivebox/pkgs/abx-plugin-singlefile/abx_plugin_singlefile/models.py
index 7e5cd41f..e5f79a99 100644
--- a/archivebox/pkgs/abx-plugin-singlefile/abx_plugin_singlefile/models.py
+++ b/archivebox/pkgs/abx-plugin-singlefile/abx_plugin_singlefile/models.py
@@ -1,14 +1,14 @@
-from django.db import models
+# from django.db import models
 
-from core.models import ArchiveResult
+# from core.models import ArchiveResult
 
-class SinglefileResultManager(models.Manager):
-    def get_queryset(self):
-        return super().get_queryset().filter(extractor='singlefile')
+# class SinglefileResultManager(models.Manager):
+#     def get_queryset(self):
+#         return super().get_queryset().filter(extractor='singlefile')
 
 
-class SinglefileResult(ArchiveResult):
-    objects = SinglefileResultManager()
+# class SinglefileResult(ArchiveResult):
+#     objects = SinglefileResultManager()
 
-    class Meta:
-        proxy = True
+#     class Meta:
+#         proxy = True