I can respond to that.
As I said earlier in a previous response, Mr. Chair, there is no manual for this outbreak. We've been learning as we go along, and the manual is literally being written. The data and the science have evolved over time, to the point that it is strongly supportive of facial coverings to this point now.
As the data and science evolve, there are multiple stakeholders as well as different guidances from various organizations. We do follow that up, as do my colleagues in the other airlines, and try to find best practices based on all these guidances.