A button (blood type)

One of the blood type emojis, it appears as a red square button representing blood type A. It is commonly used to indicate blood types or grades.

This symbol is frequently seen in hospitals and blood donation centers. Blood type A is one of the most common blood types worldwide, making it crucial for blood transfusions.

This symbol originated in 1916 when Austrian scientist Karl Landsteiner created the ABO blood type classification system. In modern times, it is also frequently used to indicate academic grades or quality ratings beyond blood types.

In the digital age, this emoji has found various uses in social media and messaging. It's often used to express superiority or excellence, and is particularly common in games and online communities to indicate rankings or grades.