As you know we originally planned to add bank-to-bank trading to RS2, but we decided to change it because we didn't want to cause a huge bank overcrowding problem. Just imagine all the players from world-1 varrock market, all crammed into one little bank, so they can bank-trade and you'll see the problem!
Today we launched a new improved 'bank note' system instead. Which still takes all the tediousness out of using certs and doesn't cause horrible crowding problems.
In RuneScape 2 when you withdraw items you can specify if you want them as an item or as a note, and it's a simple as that. So for example you can convert all the coal in your bank into 'coal notes' in one go, as you withdraw it! And when you put them back in your bank or sell them to a shop they automatically become items again. It's really very quick and easy to use
We've called them 'notes' instead of 'certs' because they aren't quite the same. The main difference is 1 note = 1 item (not 5). So for example: 1 coal note = 1 coal. This is so you aren't restricted to only trading in multiples of 5.
Also it is now possible to get notes for ALL tradeable non-stacking items, so for example you can get 'potion notes' and 'log notes' also.