According to recent studies, proper names and common nouns differ cross-linguistically with respect to their morphosyntactic behavior, i.e. their marking for case, definiteness, number and gender, among other grammatical categories. Consequently, it has been argued that proper names possess a special onymic grammar. This study is meant to contribute to the discussion by comparing the marking of definiteness and specificity (D-marking) on proper names and common nouns in a sample of fifty areally, genetically, and typologically unrelated languages. The results show that there is only weak evidence for a differential D-marking of names.