DDSXTY_ — Ambiguous description of serializing discovery types

The definition of PID_LIST_END in Table 27 in section 7.4.1.2.1, Interpretation of Parameter ID Values, reads:

RTPS specifies that the PID value 1 shall be used to terminate parameter lists within the DDS built-in topic data types. Rather than reserving this parameter ID for all types, thereby complicating the member ID-to-parameter ID mapping rules for all producers and consumers of this Data Representation, Simple Discovery types only shall be subject to a special case: member ID 1 shall not be used, and either parameter ID 0x3F02 or parameter ID 1 shall terminate the parameter list.

The meaning of “Simple Discovery types” is not clear. It should not apply to all mutable types that might ever be used as part of the Simple Discovery process. It is intended only to maintain backward compatibility with types defined in DDS-RTPS.

Proposed Resolution:

See the Proposed Revised Text below.

Proposed Revised Text:

Append an additional sentence: “These types consist of the built-in topic data types, and those other types that contain them as members, as defined by [RTPS].”

See the Revised Text below