[comp.sys.ibm.pc] Which alphabet letter is less used?

sierra@lll-tis.arpa (Frankie Sierra) (07/30/87)

I am working on a pattern matching routine for a header signature.
To avoid running through many possible matches, I will like to
start the looked-for pattern with an ASCII character that is rarely
used on any kind of text file.  The only restriction is that the
character must be a printable one (no control chars allowed).
Thus my question is:

    1. Which alphabetic letter is the least frequently used
       (among lower and upper case on text files)?
    2. Which special character ('@#$%^...etc) is the least
       frequently used on electronic mail files?


Frankie Sierra
sierra@lll-tis.ARPA