This defines a symbolic name for an integer type attribute. When setting the value of an integer attribute in a check or reply item, you can use the symbolic name instead of the raw integer.

VALUE Service-Type Login-User 1

VALUE is a keyword that says this is a value definition. Service-Type means that this is a definition of a value for the Service-Type attribute (which should be of type integer). Login-User is the symbolic name for the value, and 1 is the value that Login-User translates to. value may be in decimal or hex (prefixed by ‘0x’).

If you redefine a VALUE by defining a new name for a previously defined value number, the new definition will silently replace the old one. The first will be a synonym for the second when used in a reply.