There are 5 target rows - The two rows with the largest aircraft are numbered with Roman numerals (top row backward from VIII to V, below forward from I to IV). The two rows with the middle targets have numbers from 1 to 4 and from 5 to 8. The small targets on the right/bottom are numbered consecutively from 1 to 4.
Source: Landesvermessung und Geobasisinformation Brandenburg (LGB), Datenlizenz Deutschland - Namensnennung - Version 2.0, © GeoBasis-DE/LGB, dl-de/by-2-0, (Kontrast erhöht)