@Mike this doesn't seem to be the case any more? I'm using v1.4.7 and I'm seeing Size 3 as being "normal" such that if you make text explicitly Size 3, it is exactly the same as the default text.
Also, we have a situation where - because of changing the base font used across the site which is slightly smaller than the default and thus we've increased font sizes everywhere - we have font size 4 smaller than font size 3 because 4 is hard-coded to 15px while size 3 is variable based on stylesheet settings.
I would have thought it would make more sense to use relative sizings for fonts? If size 4 is supposed to be "normal", then have size 3 as something like 90% of size 4 and size 5 as 110% ... or something along those lines.
Either way, is there a technical reason why the font sizes (except "normal") are hard coded? Could this be made configurable by style/CSS adjustments?