diff --git a/index.bs b/index.bs
index b124f650..169d24dc 100644
--- a/index.bs
+++ b/index.bs
@@ -1842,12 +1842,11 @@ NOTE: This behavior is to allow future versions of this specification to define
 
 This section specifies the conformance points of the simple profile.
 
-Restrictions on the [=IA Sequence=]:
+When the [=primary_profile=] field set to 0, the following constraints apply to the [=IA Sequence=]:
 
 - There SHALL be only one unique [=Audio Element OBU=].
 - There SHALL NOT be any [=Temporal Delimiter OBU=]s present.
-- [=additional_profile=] SHALL be set to 0 to indicate that the [=IA Sequence=] complies with this profile.
-- [=primary_profile=] SHALL be set to 0.
+
 
 
 Capabilities of the IA parser, decoder, and processor:
@@ -1860,7 +1859,7 @@ Capabilities of the IA parser, decoder, and processor:
 
 This section specifies the conformance points of the base profile.
 
-Restrictions on the [=IA Sequence=]:
+When the [=primary_profile=] field set to 1, the following constraints apply to the [=IA Sequence=]:
 - There SHALL be at most two unique [=Audio Element OBU=]s at any one time.
 	- There SHALL be at most one Channel-based [=Audio Element=] having [=num_layers=] > 1 at any one time.
 	- There SHALL be at most one Scene-based [=Audio Element=] at any one time.
@@ -1870,13 +1869,11 @@ Restrictions on the [=IA Sequence=]:
 		- Scene-based [=Audio Element=] + Channel-based [=Audio Element=] having [=num_layers=] = 1.
 		- Scene-based [=Audio Element=] + Channel-based [=Audio Element=] having [=num_layers=] > 1.
 - There MAY be [=Temporal Delimiter OBU=]s present. If present, the first OBU of every [=Temporal Unit=] SHALL be the [=Temporal Delimiter OBU=].
-- [=additional_profile=] SHALL be set to 1 to indicate that the [=IA Sequence=] complies with this profile.
-- [=primary_profile=] MAY be set to 0 or 1.
 
 
 Capabilities of the IA parser, decoder, and processor:
-- They SHALL be able to parse an [=IA Sequence=] with [=primary_profile=] = 0 or 1.
 - They SHALL be able to support the capabilities of the [[#profiles-simple|Simple Profile]].
+- They SHALL be able to parse an [=IA Sequence=] with [=primary_profile=] = 1.
 - They SHALL be able to handle up to 18 channels.
 	- The 18 channels limit applies to the sum of channels across all [=Audio Element=]s in a [=Mix Presentation=] before mixing.
 	- One example is a mix with 3rd-order Ambisonics (16 channels) + non-diegetic stereo (2 channels).