Got this beauty in the mail today. It's a piece of postal stationery from the German Offices in China (Mi P12). What makes it unusual is the usage. First, a little background...
In the late 19th century, Germany had a leased protectorate in Kiautschou, China. It's capital was the city of Tsingtau. Surrounding the leased territory was a 50km neutral zone. Within the protectorate and the neutral zone, postage of German Kiautschou was used.
At the same time, German had post offices throughout the major cities of China (the non-leased part). These postal agencies used postage of the German Offices Abroad in China.
From 1899-1904, the Schantung Railroad was constructed to connect Tsingtau (in Kiautschou) with Tsinanfu (in China). As new stations were established along the line, the Germans opened postal agencies in the stations. This presented a problem, however -- the Chinese objected to the opening of new German post offices in the non-leased territories.
Post offices along the Shingtau RailroadTo work around this problem, the new, "provisional" postal agencies in the no-leased portions of the railroad were given double-ring cancelers which where to be used on the mail, but not on the stamps themselves. The stamps would be canceled on the trains using the official railroad cancelers, which were permitted by the Chinese.

This postal stationery card was initially canceled by the provisional post office in Tschoutsun, China. It was then officially canceled on Train #1 (ZUG 1) of the Tsingtau-Weihsien line on 7 December 1903. It arrived at the Weihsien post office the same day.
The following day, the reply card portion was canceled at Weihsien, China. It was then marked with an arrival cancel at Tschoutsun.
This card is a particular rarity because it bears not only a fairly unusual Tsingtau-Weihsien Bahnpost cancel, but two rare Tschoutsun provisional cancels. The Tschoutsun provisional cancel was only used for 2 months, and is the rarest of the provisional railroad post office cancels.
Not bad for a bargain pickup on
ebay. Anyone speak Mandarin?