Using a ``++type="timestamp"++`` column as the primary key of a table is slightly risky. Two threads could create new objects in the table close enough in sequence for them to both have the same timestamp. Alternately, this could happen during a daylight savings time change. Instead, use a numeric value as the ``++@Id++``.
This rule raises an issue when a time or date-related class is annotated with ``++@Id++``.