Changes

<cmd>usetypescriptfile</cmd> }} loads a given file ([[source:type-gyr.tex|type-gyr.tex]] in this case). This file usually contains definitions of ''typescripts''. The core typescript files (such as [[source:type-tmf.tex|type-tmf.tex]], [[source:type-one.tex|type-one.tex]] in pdTeX or [[source:type-otf.tex|type-otf.tex]] in LuaTeX/XeTeX, ...) are already preloaded, so you would usually need this only to load your own definitions. <code>\usetypescriptfile[type-gyr]</code> will soon become obsolete (TeX Gyre will be the default).

<cmd>usetypescript</cmd> }} kind of "selects" (?) the specified typescript from that file. It takes up to three parametres and their rôles are still cryptic to me...

One of the keys for defining typescripts is clever usage of the <cmd>definefontsynonym</cmd> }} command. It takes 2 or three parameters. Example from mfonts.pdf: