Subject: How safe is a character

From: [email-masked]
Date: Thu, 7 Feb 91 13:24:00 EST

Just a little comment after reading comments about how "safe"
is an encoded (uuencode or atob or pure GB) file passing
through certain odd-ball computer systems.

Yes, certain characters are subject to distortion when passing
through certain mainframe systems. I don't remember the list
of these endangered characters but I think it includes "back
quot", "backslash", etc.

One of my friends happened to reside on one such machine. I had
extensive experience able exchanging various encoded files with
him. There's a difference between uuencoded and 'zW' (pure GB)
texts in terms of the "amount of damage" that they can substain:

- 'zW' (pure GB):  very tolerate. If a character is changed by
  the mail system, only one corresponding Chinese character is
  changed. One can still guess the meaning of the sentence from
  context.

- uuencode: depends. Sometimes the program would refuse to decode
   it altogether, in which case the encoded text is useless. Other
  times the decoding succeeds, but the damage seem quite extensive
  - affects more than one Chinese characters.

Exactly what coding scheme to use depends a lot on one's objective.
But I think its not a good idea to design an encoding scheme around
some software bugs - it's a case of confusing the ends and the means,
I think.

yawei