[layer8]

To be fair, here is the RFC meaning:

   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.

It means you can’t simply ignore it, and instead have to have compelling reasons to justify any deviation.

[valley_guy_12]

Unfortunately, in many organizations, "the library we use doesn't follow this recommendation" is a valid compelling reason. Which means that in practice "SHOULD" effectively means "WOULD BE NICE IF".