[XeTeX] prioritizing OTF fonts

[maxwell]

Does fontspec load *only* OpenType fonts?

The intro to the fontspec package documentation says
     The fontspec package allows users of either XETEX or
     LuaTEX to load OpenType fonts in a LATEX document.
Does that mean it doesn't load TrueType etc. fonts, even if there are no 
OpenType versions of those fonts?

Some of the things I've read on-line (like 
http://tex.stackexchange.com/questions/241927/problem-using-ttf-fonts-with-xelatex) 
seem to imply that fontspec loads ttf fonts just fine.  In which case 
I'll have a different question: how to ensure that it prioritizes OTF 
fonts over TTF fonts fc-list finds two such fonts.
-- 
	Mike Maxwell