Suggestion: support a "fontweight" attribute
It seems to be impossible to specify font weights and styles in the DOT language except by mangling the fontname attribute value. If the renderer can grok the fontname, e.g. fontname="Times-Bold", it will export font-family="Times,serif" font-weight=600" in SVG files, for example, and it will be correctly rendered. But there is no way to know for which fonts this will actually work. And if you write the font family name out entirely, e.g. fontname="Times New Roman-Bold", it doesn't work (and the font family is not correctly rendered, either). One could say that this is somewhat less than orthogonal.
Why can't we simply write fontname="Times New Roman" (or any other name with spaces, of which there are quite a few) and fontweight="bold" (or alternatively fontweight=700)?
How much effort would it take to implement this?