This document defines two YANG modules to define support for MPLS Maximum SID Depths (MSDs). One module contains definitions for the MSD types defined in the IANA IGP MSD-Types registry. The other augments YANG modules from several other RFCs. I am not a YANG expert and made no attempt to verify the YANG modules. The draft appears to be in good shape overall. The security considerations seem appropriate to me. A couple of editorial nits are below.

In the second paragraph of the introduction, "IANA the IGP MSD-Types registry" should probably be "IANA IGP MSD-Types registry." The last paragraph of the security considerations is unnecessarily indented.