identity rcs-algorithm-base-type {
    description
      "Identify which algorithm is used to compute RCS.
       The algorithm also defines the size of the RCS field.";
    reference
      "RFC 8724 SCHC: Generic Framework for Static Context Header
                Compression and Fragmentation";
  }

  identity rcs-crc32 {
    base rcs-algorithm-base-type;
    description
      "CRC32 defined as default RCS in RFC 8724.  This RCS is
       4 bytes long.";
    reference
      "RFC 8724 SCHC: Generic Framework for Static Context Header
                Compression and Fragmentation";
  }

  typedef rcs-algorithm-type {
    type identityref {
      base rcs-algorithm-base-type;
    }
    description
      "Define the type for RCS algorithm in Rules.";
  }