UIC passenger coach types

The UIC type X, Y and Z coaches are passenger coaches for international railway services that have been standardised in certain respects by the International Union of Railways ("Union internationale des chemins de fer" or UIC).
In 1961 types X and Y were defined in UIC Leaflet 567, the type Z followed subsequently. This standardisation was intended to give rail passengers on international services a standard level of comfort; in addition it was intended to simplify the maintenance of coaches when abroad. One of the standards introduced was the use of rubber corridor connectors on gangways instead of bellows.
UIC type X.
The UIC type X was based on the express coaches developed after the Second World War by the Deutsche Bundesbahn (DB). These coaches were 26.4 m long and had doors at each end as well as compartments opening off a corridor as follows:
Composite coaches usually had six 2nd class compartments and five 1st class compartments
Type X coaches went into service in many countries, the largest numbers being deployed by the DB and the Italian state railways.
UIC type Y.
The UIC type Y was based on French proposals for an international express coach ("Schnellzugwagen"). Important differences from the type X were its shorter length and greater number of seats in 2nd class compartments. The coaches were long, the doors were also at the ends and a corridor coach configuration was standard:
The French state railway, SNCF, had composite coaches, sleepers, dining cars and coaches with a luggage section built as part of the same series.
UIC type Z.
With the development of Eurofima coaches a new level of comfort was achieved; the number of compartments was reduced whilst keeping to the same overall length, the coaches were also air-conditioned. These coaches were designated from 1976 as type Z. But because various railways still did not want to procure air-conditioned coaches or wanted to reduce the number of compartments compared with the type X (the SBB on all its acquisitions since 1969), the class was eventually divided into Z1 and Z2:
namely:
Composite coaches usually had 6 2nd class compartments and 4 1st class compartments
On the Eurofima coach the gangway was changed from the folding doors characteristic of type X and Y to pneumatically-operated swinging-sliding doors.