As you can see at
Escape Sequences (C)[
^], the escape sequence
\f
is included in
C++ and stays for
formfeed.
About the
\u
escape sequence, I suppose that in
Json it should be treated as
unicode character in hexadecimal notation (i.e. in the same way the
\xhhhh
escape sequence is treated by
C++).
Cheers,
Sauro