SC1000

$ is not used specially and should therefore be escaped.

Problematic code:

echo "$"

Correct code:

echo "\$"

Rationale:

$ is special in double quotes, but there are some cases where it's interpreted literally:

1. Following a backslash: echo "\$"
2. In a context where the shell can't make sense of it, such as at the end of the string, ("foo$") or before some constructs ("$'foo'").

To avoid relying on strange and shell-specific behavior, any $ intended to be literal should be escaped with a backslash.