From our 744/748 FCOM:
Takeoff/Landing Crosswind Guidelines
The crosswind guidelines shown below were derived through flight test data and
engineering analysis. These crosswind guidelines are based on steady wind (no
gust) conditions and include all engines operating and engine inoperative. Gust
effects were evaluated and tend to increase pilot workload without significantly
affecting the recommended guidelines.
Without further annotation, the definition remains -- steady wind only is considered.