roles Vs instances in collaboration diagrams

[Royski]

Collaboration diagrams can be specification or instance level. specification level uses class roles rather than instances. The syntax differs between a role and an instance: the role name is NOT underlined, whereas the instance name is. I've found with EA that a role can only be acheived if the role is NOT anonymous (in other words, you add text to the role field). But the UML spec suggests that un-named roles are permissible. The following would be a role: :BankAccount, whereas an instance would be: :BankAccount. Is it me that is missing something, or EA?