I sometimes wonder if there are more informed users of Australia Post than staff.
The last time I went in to a (full branch) Post Office, the person who served me asked what they did with a multiple item registered form.....
To be fair, I think they were a trainee, but they have been there for at least a couple of weeks.
Another time I was asked to do the pink 'Dangerous Goods' declaration - for a large letter. (Only necessary for parcels).
..... and the number of times I've pulled them up for wanting to charge parcel rate for a large letter...!!! (We have our own AP gauge and cut packing material to fit. Had a lot of practice on this one.

)