A Button (blood Type) on Facebook

What it signals here

reaction meaning

Rarely used as a reaction; more likely to appear in comments as a decorative A.

comment use

Older users may use it to comment 'A' in response to something they agree with or find outstanding.

boomer interpretation

May be interpreted literally as indicating blood type A or simply as a decorative letter.

group use

Used in group posts to label items, options in a poll, or categories starting with A.

See it elsewhere