I have reviewed this document as part of the security directorate's ongoing effort to review all IETF documents being processed by the IESG. These comments were written primarily for the benefit of the security area directors. Document editors and WG chairs should treat these comments just like any other last call comments.

Summary: this document is intended to clarify the relationship of SRv6 SIDs to the IPv6 Addressing Architecture.

Major issue: 
The document explains the SRv6 SID characteristics very well, which was the repeat of RFC8754. 
As the SRv6 SID is the same as the IPv6 address, the document fails to explain if there are any forwarding behavior differences on the  non-SRv6 capable intermediate nodes. 
As the intermediate SRv6 nodes use the next SID (a standard IPv6 address) as the packet's outer destination, does it mean that those non-SRv6 intermediate nodes forward the packets the same as before?  If Yes, why need this document? 

What if a malicious Man-in-middle actor alters the SID sequence in the SRH? and a non-SRv6 intermediate node does not having the address in its Forwarding Table? 

Thank you, 
Linda