David,
It seems to be the most simple things that elude me, so please help me understand what I may have missed after reading this thread.

After reviewing DMM 601.4.3, it is my understanding that tape shall not be used for packages, but is allowed to augment (strengthen) the adhesive on envelopes. So if the adhesive is not sealed, then the tape in turn is void, but if the adhesive is sealed, then tape is permitted? What I am I missing here? Maybe I am just tired.