The paper discusses the bibliographic identities of the persons who are creators or producers, or are the subject of a work. Today, in cataloguing, there are two ways to treat a person who uses more than one bibliographic identity, pseudonyms or other forms of the name: 1. as several separate persons, with an authorized form for every (individual) name with additional controlled access points for variant forms of the name, 2. as one person, with a single authorized access point (uniform heading) that would gather complete works of the person or a corporate body. The other names (personas) are treated as the variant form of the name. Heteronyms (the term heteronym is taken from linguistics) are illustrated by various examples such as the writer Fernando Pessoa, who established over seventy bibliographic identities with their own physical appearance, biography and different styles of writing, or Olja Savicevic-Ivancevic, perhaps the most famous person in Croatia using a heteronym. Unlike the pseudonym, which is just the writer's alias, the heteronym changes not only the name but also the nature and characteristics of the person. Exonyms and endonyms (the terms exonym and endonym are taken from ethnolinguistics) are illustrated by the examples of controlled access point for the entity person and entity place. The paper also presents cataloging practices of the national libraries in the world and in Croatia regarding the use of multiple names for the same creator and their attitudes to exonyms and endonyms. The quoted examples of bibliographic records from the world national libraries show title authority data made in national languages and in Latin, too.