The enhanced company branding feature is now generally available on your organization’s Azure Active Directory (Azure AD) sign-in page. Use this feature to add hyperlinks and simple formatting such as bolding, underlining, and italics.
Supported syntax
Hyperlink: [text](link)
Bold: **text** or __text__
Italics: *text* or _text_
Underline: ++text++
Learn more about the enhanced feature.