Jeff Sutherland writes in Scrum:
The thing that cripples communication saturation is specialization — the number of roles and titles in a group. If people have a special title, they tend to do only things that seem a match for that title. And to protect the power of that role, they tend to hold on to specific knowledge.
So we got rid of all titles. I called everyone and told them to rip up their business cards. If someone wanted to put a title on their resume, they could do it for external use only. In here, where the work was done, there were only team members. (emphasis added)