BIMI (Brand Indicators for Message Identification)
A DNS record that lets mailbox providers show your logo next to your mail, once DMARC is enforced and the logo is a verified SVG.
BIMI is the mechanism behind the brand logos you see next to some senders in Gmail, Yahoo or Apple Mail. The domain publishes a TXT record at default._bimi.<domain> with the URL of an SVG logo and, usually, the URL of a certificate that proves the logo is yours.
It only works on top of DMARC at p=quarantine or p=reject with pct=100; a domain at p=none gets no logo whatever the record says. The logo must be SVG Tiny Portable/Secure (a restricted SVG with no scripts or external references), square, and served over HTTPS.
Gmail and Apple Mail additionally require a Verified Mark Certificate, which needs a registered trademark, or the newer Common Mark Certificate for a logo in use for at least a year. Yahoo shows logos without a certificate. Providers also weigh sending reputation, so a brand-new domain may not get the logo even with everything in place.