On the other hand, in favour of "B": (i) It would be more useful. (ii) It would be more easily applied, as it is very difficult to draw the line as to what is "military". 5. Although the preparation of a Grey List is less urgent than that of a Black List and should not interfere with the latter, an early decision is necessary for two reasons. First, although the information is not urgently required and there is little danger of concealment by the enemy, it is important that we should get the information not later than our two main allies.