Team organization

https://groups.google.com/d/topic/django-developers/8b-wxEzWO3c/discussion
As a matter of practice, I try to avoid using the word "should."  In this case (and in my experience, in most cases) it introduces ambiguity.  What does "should" mean here?  Does it mean "in order to be counted?"

Perhaps, "Votes cast within one week will be counted.  Votes after this period may be counted in some circumstances, but may also be disregarded."