Python Regulare Expression

[stahorse]

I have this code here and I want to know how to interpret it:

found = re.findall(
        r'encoding="UTF-8"\?>(.*?)^<\?xml version="1.0"', clean, re.M | re.S,
    )

I can see where "Clean" comes from, but not sure what is "re.M" and "re.S". Can I please get an explanation of the whole syntax.

[buran]

The docs:
https://docs.python.org/3/library/re.html#re.M
https://docs.python.org/3/library/re.html#re.S