Delivery from the office of posting. Items of pneumatic mail are found with the same cancel for despatch and arrival. These would have handed in at the office, or more likely been posted in a red letter box, to take advantage of the speedy delivery service and if appropriate the "wait 5 minutes for a reply". They may well be unfolded.
Additional franking for local delivery. Items occur with additional franking, but addressed within Vienna. These show the use of the pneumatic system for quick delivery to the nearest office, after which the item was put in the ordinary post. This was relatively common from 1881, and superseded by the Express Delivery system introduced in 1887.
How long did deliveries take? Rarely, a reply-paid postcard was sent back with the first part still attached. Some of these allow one to work out how long the round trip took.
Stuck-on labels? Brown stuck-on labels were used, typically by a delivery man explaining why an item was undeliverable. Several examples are illustrated.