Joint Or Multiple Country Issues

Austria - Czech Republic Joint Issue
World Philatelic Exhibition
Septem 12 2008
The joint issue features painting Stagecoach of the Vienna Brünn line by Karl Schnorpfeil (1875-1937).

Portugal – Singapore Joint Issue
Diplomatic Relationship
May 28, 2021
The joint issue features the artistic impressions of Gardens by the Bay (Singapore) and Lisbon (Portugal).

Moldova – Romania Joint Issue
Viticulture
November 24, 2021
The stamp set features Zghihara Grapes from Romania and Rara Neagr#259; Grapes from Moldova.

Poland – Croatia Joint Issue
Treasures of the Earth – Salt
December 2, 2021
The stamp set depicts Ston Saltworks in Croatia and Bochnia Salt Mine in Poland.

Tunisia – Morocco Joint Issue
Musical Instruments
December 2, 2021
The stamps depict Stambali music of Tunisia and Gnaoua music of Morocco.

Japan – Singapore Joint Issue
50 Years of Diplomatic Relationship
November 29, 2016
The stamp set depicts traditional cooking pots (Singapore) and serving bowls (Japan).

Croatia - Switzerland Joint Issue
Lakes
May 5, 2022
The stamp set features Lake Cauma (Switzerland) and Lake Visovac (Croatia).

Luxembourg – Lithuania Joint Issue
European Capital of Culture
May 2022
The stamp set features art Nemrod by Foni Tissen (1905-1979) and Bathing by Stasys Ušinskas (1905-1974).

Two sets about WWI jointly issued by Israel and Australia on May 10, 2013. Information from the Israeli Philatelic Service web site:

The Australian Light Horse
The "Australian Soldier Park" was founded in Beersheba in 2008 to highlight the Australian Light Horsemen's heroism and commemorate the memory of the fallen. At the center of the park stands a bronze statue of a mounted Australian light horseman, depicting the moment when the light horsemen breached the Ottoman army's positions. A photo of the statue is featured on the stamp, against the background of a group of Australian light horsemen. The Israeli stamp tab features the Rising Sun ANZAC Hat Badge:


The Battle of Beersheba 1917
The Light Horse charge during the battle of Beersheba holds a significant place in the Australian army's battle lore. The photograph that appears on the stamp was taken during a reenactment of the battle that was conducted a year after Beersheba was conquered. The Israeli stamp tab features the ANZAC Slouch Hat worn by ANZAC soldiers in the Battle of Beersheba:

Germany – Czech Republic – Slovakia Joint Issue
600 years of Johannes von Nepomuk Death
March 11, 1993
The design shows statue of St. John of Nepomuk and Charles Bridge in Prague.

Brazil – Estonia Joint Issue
Centenary of Estonia-Brazil Diplomatic Relations
November 10, 2021
The stamp shows modern architecture in Brasilia and Tallinn.

Rather odd that there should be a joint Australia-Israel issue for the battle of Beersheba, which had no connection with Zionism, but was militarily linked with the Arab Revolt.

Croatia - Kyrgyzstan Joint Issue
Woodpeckers
2021
The stamp set features Red-Headed Woodpecker (Dendrocoptes medius) and White-Winged Woodpecker (Dendrocopos leucopterus).

Algeria - Tunisia Joint Issue
Medjerda River
October 24, 2021
The joint issue features a view of the Medjerda River, a 450 km long river flowing from northeast Algeria through Tunisia before emptying into the Gulf of Tunis.

Japan – France Joint Issue
Mailboxes
October 11, 2021
The stamp set features stylized traditional French and Japanese mailboxes.