Mr. Usher said Microsoft was also considering its legal options, which could include a civil lawsuit.
Another national walkout is planned for June, which could include the National Union of Teachers.
Plans run the gamut from telephone advice only to comprehensive services, which could include trial representation.
Its authors call for discussion on ways forward, which could include taxes of sweet calorific drinks.
The suspects were detained on Tuesday and later released pending formal charges, which could include murder.
Hotels, golf courses and "specialist use property" - which could include hospitals and prisons - could be excluded.
China has threatened to retaliate against tariffs, which could include action against US companies operating there.
If it does not, the UN will consider "measures", which could include sanctions of some sort.
Officials are still exploring plans for the property, which could include a park.
On May 1, the company reported that it was exploring strategic options, which could include a sale.
Critics, however, have long maintained that an orderly mass evacuation, which could include New York City, is virtually impossible.
