A, B and O are pretty useful letters. If they disappeared tomorrow, society would be in chaos. But A, B and O are also different blood types, and without them...well...society wouldn't even exist. To highlight this, a new campaign is asking companies to drop these letters from their logos, and a number of major global brands and landmarks have already joined the cause.

The campaign, that goes by the hashtag #MissingType, is a collaboration between NHS Blood and Transplant and London-based PR agency Engine Group, and the purpose of the initiative is to raise awareness about blood donation for National Blood Week. The amount of blood being donated internationally has dropped by 30 percent in the last decade, and major brands such as Google, Microsoft, Tesco, Nandos and Dairy Milk are dropping their letters to show their support.

The campaign runs from August 16th until August 21st across 21 countries. It also brings together 25 blood services from participating countries including the US, Australia, Singapore, South Africa, Ireland and Canada.

More info: Twitter | NHS Blood and Transplant | YouTube