Original text:
6.  In this section we describe the structure and methods to be used when doing MAC authentication in COSE.  This document allows for the use of all of the same classes of recipient algorithms as are allowed for The CDDL fragment which represents the above text for COSE_Mac follows. <del> 6.1. </del>  In order to get a consistent encoding of the data to be authenticated, the MAC_structure is used to have a canonical form. in order are: A text string that identifies the structure that is being encoded. <del> This string is "MAC" for the COSE_Mac struture. </del>  The protected attributes from the COSE_MAC structure.  If there are no protected attributes, a zero length binary string is to be

Reviewer comments:
Everybody but me wants a MAC w/o recipients.
There also needs to be an equivalent no-recipient signature version. Thanks.
That string does not even parse.
Should the kid attribute be a binary value rather than a string value?
No arguments that binary should not be the only type for this, some questions that binary is useful based on Jose experience. Definite arguement that binary is required. Doing two types is probably a bad idea.

Revised text:
6. <ins> COSE supports two different MAC structures.  COSE_MAC is used when the key needs to be explicitly identified.  The structure supports the use of recipient structures to allow for random content encryption keys to be used.  COSE_MAC0 is used when the a recipient structure is not needed because the key to be used is implicitly known. 6.1. </ins> In this section we describe the structure and methods to be used when doing MAC authentication in COSE.  This document allows for the use of all of the same classes of recipient algorithms as are allowed for The CDDL fragment which represents the above text for COSE_Mac follows.  <ins> 6.2. In this section we describe the structure and methods to be used when doing MAC authentication for those cases where the recipient is implicitly known. The MAC message uses the COSE_Mac0 structure defined in this section for carrying the body. The MAC structure can be encoded either withor without a tag depending on the context it will be used in.  The MAC structure is identified by the CBOR tag TBD6.  The CDDL fragment that represents this is: The COSE_Mac0 structure is a CBOR array.  The fields of the array in order are: is described in header-parameters. is described in header-parameters. contains the serialized content to be MACed.  If the payload is not present in the message, the application is required to supply the payload separately.  The payload is wrapped in a bstr to ensure that it is transported without changes.  If the payload is transported separately, then a null CBOR object is placed in this location and it is the responsibility of the application to ensure that it will be transported without changes. contains the MAC value. The CDDL fragment which corresponds to the above text is: 6.3. </ins> In order to get a consistent encoding of the data to be authenticated, the MAC_structure is used to have a canonical form. in order are: A text string that identifies the structure that is being encoded.  <ins> This string is "MAC" for the COSE_Mac structure.  This string is "MAC0" for the COSE_Mac0 structure. </ins> The protected attributes from the COSE_MAC structure.  If there are no protected attributes, a zero length binary string is to be