Have you noticed the correspondence between these alternate terminal incantations and the resultant codes they produce? If an ASCII table is laid out in columns of 32, they are on the same row, e.g.

     (3) ETX <-- C (67)
     (4) EOT <-- D (68)
     (8) BS  <-- H (72)
    (27) ESC <-- [ (91)

I was happy to find some order in what previously seemed arcane stuff.