Original text:
The protocol aims to be compatible with federated environments. While this document does not specify all necessary mechanisms required for federation, multiple MLS implementations can <del> interoperate and to form federated systems. </del>  3.1.7. We assume that all transport connections are secured via some transport layer security mechanism such as TLS I-D.ietf-tls-tls13. However, as noted above, the security of MLS will generally survive <del> compromise of the transport layer. </del>  3.2.2. A corollary to this statement is that the AS and the DS cannot read the content of messages sent between Members as they are not Members <del> of the Group.  MLS optionally provide additional protections </del>  regarding traffic analysis so as to reduce the ability of adversaries, or a compromised member of the messaging system, to deduce the content of the messages depending on (for example) their In general we do not consider Denial of Service (DoS) resistance to be the responsibility of the protocol.  However, it should not be <del> possible for anyone to perform a trivial DoS attack from which it is hard to recover. </del>  3.2.2.5. including total DoS attacks (where it simply refuses to forward any messages) and partial DoS attacks (where it refuses to forward messages to and from specific Clients).  As noted in delivery- <del> guarantees, these attacks are only partially detectable by clients. Ultimately, failure of the DS to provide reasonable service must be dealt with as a customer service matter, not via technology. </del>  Because the DS is responsible for providing the initial keying material to Clients, it can provide stale keys.  This does not

Reviewer comments:
Remove "join an existing group" from architecture doc, based on UserAdd having been removed from the protocol doc. Remove statement that message delivery cannot be correlated between AS identities and DS delivery channels. This seems generally very difficult to achieve. It may be possible at times, but does not seem to be grounded in discussions that we have had at the working group meetings. Note that federation requires compatible wire encodings. Note that communication with the AS requires TLS or alternative authentication. Note that out-of-band channels may facilitate detection of misbehaviour. Some grammar fixes.

Revised text:
The protocol aims to be compatible with federated environments. While this document does not specify all necessary mechanisms required for federation, multiple MLS implementations can  <ins> interoperate and to form federated systems if they use compatible wire encodings. </ins> 3.1.7. We assume that all transport connections are secured via some transport layer security mechanism such as TLS I-D.ietf-tls-tls13. However, as noted above, the security of MLS will generally survive  <ins> compromise of the transport layer, so long as identities provided by the AS are authenticated at a minimum. </ins> 3.2.2. A corollary to this statement is that the AS and the DS cannot read the content of messages sent between Members as they are not Members  <ins> of the Group.  MLS optionally provides additional protections </ins> regarding traffic analysis so as to reduce the ability of adversaries, or a compromised member of the messaging system, to deduce the content of the messages depending on (for example) their In general we do not consider Denial of Service (DoS) resistance to be the responsibility of the protocol.  However, it should not be  <ins> possible for anyone aside from the DS to perform a trivial DoS attack from which it is hard to recover. </ins> 3.2.2.5. including total DoS attacks (where it simply refuses to forward any messages) and partial DoS attacks (where it refuses to forward messages to and from specific Clients).  As noted in delivery-  <ins> guarantees, these attacks are only partially detectable by clients without an out-of-band channel.  Ultimately, failure of the DS to provide reasonable service must be dealt with as a customer service matter, not via technology. </ins> Because the DS is responsible for providing the initial keying material to Clients, it can provide stale keys.  This does not