Re GR square brackets

[Terrance]

"I'd argue that generally a square bracket [thus]
equates to an insertion within a quoted passage or narrative excerpt by
an
extraneous author or editor, like a stage direction in a play for
example,
whereas a regular bracket (thus) indicates an elaboration or digression
by
and consistent with the speaker/voice/narrator. Pynchon uses the latter
type
in _GR_ far more often than the former, which already marks this
particular
passage as unusual; and while there are many and varied intrusions into
the
veneer of the narrative/s this is one which has captured the imagination
of
many readers because it seems so loaded with significance and emotive
force,
but is ultimately so damned cryptic." 

Thanks, so the Square Brackets [  ], used in publishing to indicate
editorial comment or a comment from an authority, make this a very
unusual passage. Are there other examples from GR?