--- which represents the tale written as a piece of IF. That's the **source
-file** (so called because it contains the game in its original, source,
-form) which you create on your computer. The source file is a "text" (or
-"ASCII") file containing words and phrases which can be read -- admittedly
-after a little tuition, which is what this guide is all about -- by humans.
+-- which represents the tale written as a piece of IF. That's the
+:term:`source file` (so called because it contains the game in its
+original, source, form) which you create on your computer. The source file
+is a "text" (or "ASCII") file containing words and phrases which can be
+read -- admittedly after a little tuition, which is what this guide is all
+about -- by humans.