fongka2 - you haven't explained your use case, so it's not clear if you really need this or if there is some other better way to achieve it. For example with the limited alias length, it seemed to me using a message was a better way of achieving that - there was no need to store that data in the alias. Perhaps the same is the case here, but it depends on what you're trying to do. This is why our feature request guidelines include providing an explanation of these things - otherwise you're not really making a convincing case for a feature.
I often push back on feature requests, and the main reason is we perpetually have about 5 year's worth of work on the feature requests tracker, and so it's unlikely that we will be able to implement any specific request very soon, so it's important to establish that the idea really is important and doesn't have any good workarounds. Another reason is often when you dig in to what people are trying to achieve, there is already a solution, or at least some kind of workaround. So it's important to properly understand feature requests - and that sometimes means pushing back on them and asking questions - to avoid ending up spending our limited time on features that weren't really needed.