I have reviewed draft-ietf-quic-datagram-08 as an opsdir telechat
review. That the document is concise and generally well written.  I
have only two remarks, nothing that is blocking publication. The first
one is editorial, the second one is a question to explain the
motivation of an explicit Length field.

- In the description of the DATAGRAM frame below Figure 1, perhaps
  also describe the Type: field explicitly. Yes, the field is
  described in the text preceding Figure 1, but it is usually a good
  idea to describe all protocol fields separately, this makes it
  easier to find and quote the relevant bits and pieces.  The text
  above the figure can then likely be shortened. (Perhaps there is
  also no need to name the LEN bit by just referring to the frame
  type, or are there are frame times that have a LEN bit?)

    Type: The DATAGRAM frame type takes values 0x30 or 0x31. If the
       frame type is 0x31, the Length field is present. Otherwise, if
       the frame type is 0x30, the Length field is absent and the
       Datagram Data field extends to the end of the packet.

- Perhaps add some text motivating why having both frame type values
  is useful and detailing what implementations should do if things are
  inconsistent, e.g., the Length field is larger than Datagram Data.

While uploading	my review, I discovered that I reviewed this document
already	in December. I guess my	memory is getting faulty. Sorry for
making new comments I did not make before. ;-)