In Russia the doctoral degree system is two-tier.

First doctoral degree (Кandidat nauk ‘кандидат наук’, “Candidate of Science in …”)

Second doctoral degree (Doktor nauk ‘доктор наук’, “Doctor of Science in …”).

«In countries with a two-tier system of doctoral degrees, the degree of Kandidat Nauk should be considered for recognition at the level of the first doctoral degree.

In countries with only one doctoral degree, the degree of Kandidat Nauk should be considered for recognition as equivalent to this degree.

In countries with a two-tier system of doctoral degrees, the degree of Doktor Nauk should be considered for recognition at the level of the second doctoral degree.

In countries in which only one doctoral degree exists, the degree of Doktor Nauk should be considered for recognition at the level of this degree»

From: Guidelines for the recognition of Qualifications from the European Countries in the Russian Federation and of Russian Qualifications in the other European Countries // Kouptsov O. Mutual Recognition of Qualifications: the Russian Federation and Other European Countries. – Bucharest: UNESCO, 1997. – 132 pp. – ISBN 92-9069-146-8.