The Important Reasons Why Letter A, O, and B are missing From Signs In London

The missing letters are of blood types. It's a campaign launch by Give Blood NHS to boost blood donation awareness during the National Blood Week, which runs from 8–14 June.

Presently their is a year-on-year decline of blood donation, more than half of the donors are over 45-years-old. The campaign wants to encourage much people to donate, and they hope companies in the city will follow suit by joining the campaign so as to encourage their employees to donate blood.

Twitter users are encourage to remove the O,A and B in their username and companies too are expected to remove O, A and B on their signs. Some companies has responded to the campaign like Waterstones and Odeon studios. And it has been getting a lot support online too.