These rules have recently changed. Effective from April 5, 2010, a new Visa Code comes into effect. As part of the new Visa Code, Schengen Type B and Type D+C visas will no longer be issued. However, those still in circulation will still be honored.
Visas are currently granted in the following categories:
Category A refers to an airport transit visa. It is required for some few nationals for passing through the international transit area of airports during a stop-over or transfer between two sections of an international flight. The requirement to have this visa is an exception to the general right to transit without a visa through an international transit area of an airport.
Category C refers to a short-term stay visa. They are issued for reasons other than to immigrate. They entitle holders to carry out a continuous visit or several visits whose duration does not exceed three months in any half-year from the date of first entry.
Short term medical insurance would be recommended for this type of trip.
Category D refers to national visa. They are issued by a Schengen state in accordance with its national legislation as with respect to the conditions (however, a uniform sticker is used). The visa also entitles the bearer to stay in other Schengen countries for 3 months in 6 months. Before April 5, 2010, travel to other Schengen countries was only allowed after the holder had obtained a residence title after arrival in the destination country, or they had been issued the (now defunct) C+D visa.
FTD and FRTD are special visas issued for road (FTD) or rail (FRTD) transit only between mainland Russian Federation and its western exclave of Kaliningrad Oblast.