They are valid patterns in MS Word and Notepad++ search and replace, though. (Word uses parentheses to create the group then \1 to reuse it in the replacement s

They are valid patterns in MS Word and Notepad++ search and replace, though. (Word uses parentheses to create the group then \1 to reuse it in the replacement string, while Notepad uses $1). That's what I meant about every system using a different syntax for what's basically the same functionality.