Controlled User Data Entry

It would be fantastic if there was a user data entry control where the Axiom developer could define the allowable selections for user data from a dropdown list for committing into the historian.  This would allow for more manageable data and expand it's usefulness.   Right now user entered data is a free-for-all string entry.  Think reason codes for machine state.  If Canary/Axiom had this feature, I may not be considering a SCADA platform simply for user entered data.  Thank you for your time!