How do I indicate the number and series of my birth certificate when buying a ticket online?

How do I indicate the number and series of my birth certificate when buying a ticket online?

Enter the series and number of the document in the field, replacing Russian letters with Latin ones. For example, IV-ЖА is entered as IVZHA. If you doubt that you will indicate the series and number correctly in Latin, write in Russian. As soon as you enter, a prompt appears with the correct transliteration. Click on it - and the letters will be substituted in the field.

The format for entering the number of a birth certificate issued in the Russian Federation (SR): Series: Roman numerals (you must type in the Latin register letters I, V, X), two letters in the Russian keyboard layout, number: 6 (six) digits. Dashes and spaces are irrelevant.