Hi,
In the single line mode which can be turned on by using (?s), the dot “.” character matches all characters, which normally matches any character except the new line character e.g. \n.
In the multiline mode which can be turned on by using (?m), the caret “^” and dollar “$” signs match the beginning and the end of each line instead of only matching the beginning and the end of the string.
Best,
Armin