+ Matching for ship patterns in /a and /d commands picks the first
+ of the following which applies and is not contradicted by any
+ name or partial name specified in the command:
+ - The ship we think the person telling us is on board
+ - The ship we think we are on board
+ - Any other ship we know about, if at least a something was
+ specified, and provided that is not ambiguous
+ - The specific ship name if it is completely specified,
+ possibly recording this as a new ship
+