Unfortunately it is not possible to support both UTF-8 and codepages at the same time without compromising the way encodings are handled eg. mIRC would have to use a hybrid UTF-8 codepage combination that would not be valid UTF-8.
mIRC v6.35 did attempt to handle multiple encodings, using some rather messy kludges, and because of that users constantly reported issues with corrupted text.
The issue with codepages is most obvious in the channels list window. The channels list window lists thousands of channel names, many of which use codepage-specific encodings. However the window can only display text using one codepage. That means that channel names not using that specific codepage will be displayed incorrectly. The same issue applies to all channel and query windows where users chat in multiple languages.
While it may seem that mIRC v6.35 handles codepages correctly, there are a large number of situations where it cannot do so due to a lack of context, just like in the channels list window.
I realize that many channels use codepages and that this will be an issue for them. However, there needs to be a transition to UTF-8. The first step was to make mIRC v6.35 display UTF-8 by default. The next step, as far as I can see, is to make mIRC send UTF-8 text consistently.
