Summary of DDL/DML statement return/output values?

First time poster here, big fan of all the work you do.

When interacting with the server through all the various types of DML and DDL statements, the return message that the server sends back to the client varies in content and format.  For example, a response to a CREATE TABLE is just "CREATE TABLE" (so, no change in tense e.g. 'CREATED', or a table name acknowledgement or something), whereas a COPY command yields "COPY <rowcount>", and the output from an INSERT is "INSERT <oids> <rowcount>".  CREATE TABLE AS SELECT (...) yields a reply of "SELECT <rowcount>", very different from other variations of the CREATE TABLE statement.  The variation in format is of course necessary, since the various SQL statements do very different things.

However, for some statements PG's output format is documented (e.g. INSERT, EXPLAIN), and in others it is not (e.g. SET, CREATE TABLE, ALTER TABLE, etc).  The output-control RETURNING clause gets its own page, but I'm unaware of any other meta-summary of output values.

I'm asking because I'm considering proposing a feature request to the hackers list that would alter response output under certain circumstances, and was looking to educate myself about the full scope of current server outputs.  So I was a little surprised when I couldn't readily find that information, given the thoroughness of documentation in every other respect.

Thanks for your help,

Steve Estes