Security Assertion Markup Language, aka Security Assertion Markup Language, is a xml format created in 2001.

Security Assertion Markup Language (SAML, pronounced sam-el) is an open standard for exchanging authentication and authorization data between parties, in particular, between an identity provider and a service provider. As its name implies, SAML is an XML-based markup language for security assertions (statements that service providers use to make access-control decisions). SAML is also: A set of XML-based protocol messages A set of protocol message bindings A set of profiles (utilizing all of the above)The single most important use case that SAML addresses is web browser single sign-on (SSO). Read more on Wikipedia...

• Security Assertion Markup Language Wikipedia page
• Security Assertion Markup Language first developed in Organization for the Advancement of Structured Information Standards