There is no universal answer as it depends on which IDP/federation you use and what is supported by it.
Generally, the friendly name is just a human-readable identifier for the attribute and the value can be freely defined.
The NameFormat and Name are defined based on Attribute Profile used by your IDP (e.g. Basic profile, X.500/LDAP Profile, ...). The expected values can be found in SAML 2.0 profiles document chapter 8.
You can find an example of how this is employed in practice for e.g. inCommon federation in their documentation.