XSLT 2.0 and XPath 2.0 Programmer's Reference, 4th Edition (668 page)

The
i
flag does not affect constructs other than those listed above. For example, it does not affect the meaning of
\p{Lu}
, which matches upper-case letters only, whether or not the flag is set.

The
m
flag

The
m
flag switches on multiline mode. In the default mode (called string mode) the meta-characters
∧
and
$
match the beginning and end of the input string. In multiline mode, the input string is treated as a sequence of individual lines separated by a newline (x0A) character. The meta-characters
∧
and
$
then match the beginning and end of any line.