I am just reading the Embraer General Publication "Understanding Vref and Approach Speeds." Amongst other things, it states:
During certification, the actual landing distance is demonstrated as
follows:
• Standard temperature.
• Landing configuration: landing gear and flaps set for landing.
• Stabilized approach at VREF.
• Changes in configuration, power or thrust, and speed, must be
made in accordance with the established procedures for
service operation.
• Determination on a level, smooth, DRY and hard-surfaced
runway.
• The landing must be made without excessive vertical
acceleration, tendency to bounce, nose over, ground loop,
porpoise, or water loop.
What, is a "water loop"? Since we are talking about a Transport Category land plane, we are evidently not talking about the seaplane equivalent of a ground loop.