Latin scientific names are used widely in the Black Sea Red Data Book to identify species. Almost all species have synonyms (other scientific names more or less widespread). Scientific orders and families are also given for species. To facilitate navigation in the list of species included in the Red Data Book they are divided arbitrarily into 13 groups with Latin names. The groups are listed in the main index which can be displayed in the left part of the Red Data Book window by pressing the button Index. The selection of species according to group, order, and family attributes is provided by the Search Engine. Some species are supplied with their common names in English, Bulgarian, Romanian, Russian, Turkish and Ukrainian.