Comment by piotrSikora

Why is he being downvoted?

As per RFC2119 (http://www.ietf.org/rfc/rfc2119.txt):

    3. SHOULD   This word, or the adjective "RECOMMENDED", mean that there
    may exist valid reasons in particular circumstances to ignore a
    particular item, but the full implications must be understood and
    carefully weighed before choosing a different course.