GROUPING OF AERODROMES/HELIPORTSThe criteria applied by the Republic of Lithuania in grouping aerodromes/heliports for the provision of information in this AIP are as follows:PRIMARY INTERNATIONAL AERODROME/HELIPORTAerodrome/heliport of entry and departure for international air traffic, where all formalities concerning customs, immigration, health, animal and plant quarantine and similar procedures are carried out and where air traffic services are available on a regular basis (See AD 1.3).SECONDARY INTERNATIONAL AERODROME/HELIPORTAnother aerodrome/heliport available for entry or departure of international air traffic, at which the formalities of customs, immigration, health and similar procedures and air traffic services are available on a restricted basis to flights with prior approval only. NATIONAL AERODROME/HELIPORTAn aerodrome/heliport available only for domestic air traffic, where all formalities concerning customs, immigration, health and animal and plant quarantine are not available and international traffic is allowed only under certain conditions.GENERAL AVIATION AIRFIELDAerodrome available only for domestic general aviation flights and aerial works. Information about general aviation airfields are available in the Aeronautical Information Publication for Visual Flights of the Republic of Lithuania.