Here is my YANG doctor's review of draft-ietf-netmod-rfc6991-bis-16.  


o  typedef email-address

  The domain part of "email-address" is different from the type
  "domain-name".  This looks a bit odd.  If special characters can
  occur in the domain part of an email address, one would assume that
  they can occur in a domain name as well.


o  typedef protocol-number

     "The protocol-number type represents an 8-bit Internet
      protocol number, carried in the 'protocol' field of the
      IPv4 header or in the 'next header' field of the IPv6
      header. If IPv6 extension headers are present, then the
      protocol number type represents the upper layer protocol
      number, i.e., the number of the last next header' field
                                         ^^^ ' missing
      of the IPv6 extension headers.


o  typedef ipv6-address-and-prefix

     "The ipv6-address-and-prefix type represents an IPv6
      address and an associated ipv4 prefix.

   s/ipv4 prefix/IPv6 prefix/


o  typedef ipv4-address-and-prefix

     "The ipv4-address-and-prefix type represents an IPv4
      address and an associated ipv4 prefix.

   s/ipv4 prefix/IPv4 prefix/


o  "schema node instance"

  This term is used in a few places in ietf-yang-types, for example:

      A schema node instance of this type will be set to zero (0)
      on creation

  This isn't correct, since a schema node is a node in the schema
  tree, and doesn't have a value.  With RFC 7950 terminology, it would
  be "a node in the data tree".  It is unfortunate that there is no
  specific term for this in RFC 7950.

  Perhaps it would be easier to just write "An instance of this
  type...".

  (I know that this was not correct RFC 6991 either)


/martin