| => param delimiter (as it is today) `| => literal pipe `a => `a (when anything other than a pipe follows a backtick, keep the backtick and the char) `` => `` (same as above, effectively) `| => ` followed by param delimiter \a => \a (backslash only has special meaning when preceding a backtick) \ => \ (same as above)
What parses to '| ? Now you have two escape characters, which just makes it more confusing, if you ask me.