[rt-users] RealName instead of Name

[Milos.Barina]

Hi everyone,

after migrating to RT 3.8.7 from 3.6.3, users in drop-down fields  (e.g. QueryBuilder) are shown as RealName instead of Name.  This is considered an inconvenience by some people. 
Is there an administrative setting to change it back? If not, what would be the recommended way to change it back in the code?

Thank you in advance for any hint.

Milos