(→top: make that actually work (looks right in Chrome on Mac, anyway – may need tweaks to work universally, to stop the {{PlayStation key press}} output from overlapping the {{key top}} and {{button}} output))
To indicate text is a variable name. Use for any variable names except those including "I" (uppercase i) and/or "l" (lowercase L); for these, {{varserif}} should be used to ensure a noticeable distinction
To display parameters as used in code (i.e. with triple braces), especially to indicate relationships between them. May be combined with {{para}} above
(or {{dc}} ) To indicate deprecated source code in template documentation, articles on HTML specs, etc. The {{dc2}} variant uses strike-through (<blink>) while {{dcr}} uses red (<blink>).