Unique key to this object. Unlike an Id this key can be explicitly set by the
application and is intended to be "somewhat" readable by a human.
A Key:
- A Key is used when the actual value is important
- A Key value might be kuali.org.School
- A Key on occasion may be used or seen by an end user.
- Keys are assumed to have the same values in different KS implementations
- Key values are defined in configuration
- Key values have significance in that they are referenced in Configuration
- Key values are expected to be occasionally used in application code