It would be great if we could create user-defined properties for fields.
For example, custom text properties like units (centimeters, meters, kilometers), editing instructions, etc.
This idea is a different take on the Field Description idea: https://community.esri.com/t5/data-management-ideas/field-descriptions-in-gdb/idc-p/1314298/highligh.... While the information could in theory be jammed into a description property, it would be cleaner to define separate custom properties. Separate properties would be easier to access with Python and SQL (from the system tables), compared to trying to parse the information from a description property.