You end up with A# format. Thats still valuable. For example envelopes and most bags expect A4. Also you can still use the paper gsm for example to calculate th

You end up with A# format. Thats still valuable. For example envelopes and most bags expect A4. Also you can still use the paper gsm for example to calculate the weight when its in A#. Advantages of this system are pretty hidden and subtle but when you notice it helped you then you are glad somebody put lots of thought into it. What would be better alternative? Make it random?