What do these strings, '\M^?' and '^\M?', represent in zsh/ZLE?

In the [documentation for the Zsh Line Editor](https://zsh.sourceforge.io/Doc/Release/Zsh-Line-Editor.html) , there is a section that says: For either in-string or out-string, the following escape sequences are recognised: \a bell character \b backspace \e, \E escape \f form feed \n linefeed (newline) \r carriage return \t horizontal tab \v vertical tab \NNN character code in octal \xNN character code in hexadecimal \uNNNN unicode character code in hexadecimal \UNNNNNNNN unicode character code in hexadecimal \M[-]X character with meta bit set \C[-]X control character ^X control character In all other cases, ‘\’ escapes the following character. Delete is written as ‘^?’. Note that ‘\M^?’ and ‘^\M?’ are not the same... How should those last two sequences be interpreted? My guess is: \M^? - delete with the meta bit set? ^\M? - control + question mark with the meta bit set Is this correct?