Earlier this month, the Red Cross launched the Missing Types campaign to urge the public to fill the gaps by making an appointment to give blood or platelets this summer. For example, “The _meric_n Red Cr_ss needs _l_ _d d_n_rs,” began a recent Red Cross news release. Get it? The letters A, B and O — the letters representing the main blood groups — are disappearing from brands, social media pages, signs and websites to illustrate the critical role blood donors play in helping patients. When the letters A, B and O vanish from everyday life, the gaps are striking, the release read, and when A, B, O and AB blood types go missing from hospital shelves, patient care and medical treatments are affected.