Sometimes when reviewing explain output that has been provided in isolation (of logfiles and/or the command(s) used to generate it), it can be difficult to confirm that the explain was run against the right db and/or collection.

Can the namespace please be added to the explain output? The rationale is basically the same as the addition of "serverInfo" to new style explains, ie. yes, this is info that is not directly what the user has asked for, but provides invaluable context for interpreting the rest of the results.

A top-level "ns" field as the first field would be great, and I expect it would fit in with both new and old style explains (and be straightforward to actually implement and test).