When is it ok to call MDB_NEXT_MULTIPLE?

The docs imply that the MDB_NEXT_MULTIPLE cursor operation may only be used following MDB_GET_MULTIPLE (or another MDB_NEXT_MULTIPLE). Is that the case?

In my experience MDB_NEXT_MULTIPLE has behaved the same as MDB_GET_MULTIPLE following MDB_NEXT_NODUP. That was a desirable thing in my case. I am wondering if that behavior can be depended on.

The documentation for MDB_NEXT_MULTIPLE is probably technically correct. But it is vague. I don't understand what "preparing the cursor" entails.