I think that's a useful mnemonic. And it may help people to remember that those are the
things the /m and /s modifiers affect. The /s modifier only affects whether "." will match a newline. The /m modifier only affects whether ^ and $ can match at embedded newlines in the middle of a string.
Other than that, everything else remains unaffected... in particular, "\n" and "\s" will always match newline characters, regardless of what modifiers are set.