I have a client running a (very) old version of DNN (4.09.xx) who is now having some browser compatibility issues (surprise!). I've suggested they need to upgrade and should do so ASAP however, in the in meantime I can't seem to find any info on updating the doctype.

I understand it's driven by the default.aspx file pre 4.4.x, but at a glance I can't see where/how to specify the change. Can someone offer some guidance or maybe post the actual contents of a default file where the doctype is non-default?