Fun fact. 

Bluetooth is the Anglicised version of the Scandinavian Blåtand, the epithet of King Harald Bluetooth, who united the disparate Danish tribes into a single kingdom

The Bluetooth logo merges the Younger Futhark runes ᚼ, Hagal and ᛒ, Bjarkan, Harald's initials. https://image.nostr.build/5fb21cb79767a3ded0f9b29b333805fa0838df18db4789bfe5857a2b93f556bd.jpg