This might be old news, but I can’t resist an interesting case about Trademarks – when the TARDIS is involved, I’m hooked.
In 1996, the BBC applied to register the TARDIS as a trademark with the UK Intellectual Property Office. (source) The London Metropolitan Police District (LMPD) opposed the registration on the grounds that they owned the mark and despite giving their consent to the BBC to use the iconic Police Phone Box as the TARDIS, they did not give any further permission. (source). The LMPD took the position that if the BBC was granted the mark, it would confuse and deceive the public into thinking that the MPD endorsed the products and services.
The UK IPO held that the police did not own a mark to the iconic phone box, but if they did, it would only be in the narrow category of law enforcement services – not time travel.* Furthermore, since the LMPD was not the only police force to use the Phone Box, it was not something to which the LMPD could claim exclusive rights. Accordingly, the BBC prevailed. (Decision)
*The BBC didn’t actually apply for the mark for time travel. It was for entertainment services and assorted schwag and merchandise associated with the Dr. Who TV show.