We find four different modes regarding exonyms:

1. Exonyms without additional endonyms

2. Exonyms with additional endonyms in brackets

3. Endonyms with exonyms in brackets

4. Endonyms without exonyms

Source: Wiener Schriften zur Geographie und Kartographie (click here for enlargement)

Map 1: only exonyms

Map 2: exonyms (endonyms)

Map 3: endonyms (exonyms)

Map 4: only endonyms