Old parameter info in TCP/IP callbacks?

Please is this still valid for message in TCP/IP callbacks?

# message - an ascii representation of the data
#			Unprintable characters and unicode characters will
#			not be preserved. Use the 'bytes' parameter to get
#			the raw bytes that were sent.

While doing some tests, I feel like message supports unicode characters (at least everything works while testing some utf-8 texts). Am I wrong, or this parameter info wasn’t updated during some upgrades? Thanks.