Bethesda Softworks has trademarked Fallout 4 in Europe. The discovery was made during which a Fallout 4 teaser website was uncovered. The teaser website beeps Morse code that corresponds to the sites countdown to December 11, which written in European dating style would be 11-12-13.
The Fallout 4 registration was discovered on the website of the Office for Harmonization in the Internal Markets, which is the official trademark office of the European Union. While this doesn’t confirm a 100% of the Fallout 4 existence, it does coincide with other discoveries unearthed.