Andrew Feren asekd,
| I was trying to write a rule to match dollar signs ('$'), but
| procmail always seemed to treat the $ character specially no
| matter how I quoted or escaped it. I ended up using the
| pattern "[^ -#%-~]".
Andrew's pattern, unfortunately, passes control characters and eight-bit
characters.
If there is no "$" modifier, \$ denotes a literal dollar sign. If there is a
"$" modifier, you might need \\\$.
[$] always means a literal dollar sign, with or without the "$" modifier,
so that's what I recommend. (Likewise, ($) always means a newline, with or
without the "$" modifier.)