I know it’s hard to believe that the German government would be this intrusive, but…
From No Hyphens, Please: Germany Tells Parents To Keep Names Simple:
All Germans register their names with the Standesamt, or local registry. Standards vary from place to place, and applicants who are turned down can appeal to the courts. Authorities are usually more flexible about first names than last. Among the first names approved over the years, according to the Language Society: Pumuckl, taken from a cartoon character, and Pepsi-Carola, taken from a soft drink. Rejected: Lenin, McDonald, Schnucki and Bierstüaut;bl, which translates roughly as ‘little beer pub.’A Dusseldorf court in 1998 rejected the name Chenekwahow Migiskau Nikapi-Hun-Nizeo Alessandro Majim Chayara Inti Ernesto Prithibi Kioma Pathar Henriko, on the grounds that the mother’s wish to honor multiculturalism shouldn’t result in an awkwardly long name for the child. A Frankfurt court upheld the name Jesus the same year, in part because it’s widely known that Christ was male, leaving little room for gender confusion.
Germany isn’t alone in Europe in regulating names. Slovakia, for example, forbids first names that are eccentric, derogatory or ludicrous (parents can’t name a child ‘Cigarette,’ for instance). It also generally bans hyphenated last names for children — though the Ministry of Interior says it makes an exception for the children of hyphenated foreigners living in Slovakia. Natives are allowed double surnames without hyphens.
But in Belgium, authorities in 1997 told children of a Spanish-Belgian marriage they could not switch to a Spanish-style double surname: ‘There are insufficient grounds to propose to His Majesty the King that he grant you the favor of changing your surname.’ They appealed to an EU court and won. The United Kingdom, on the other hand, imposes almost no rules.