Here is the correct formatting
Adding an extra line between the address an the signature does not make the formatting incorrect. Adding newlines and spaces to the message does however cause problems.
It used to be common practice in this thread to use code boxes to separate the items and make the boundaries clearer and keep messages to a simple one line.
Example
Message :
Today is the 13th of April 2018 and I am MyName (u=xxxxxx) staking my address on bitcointalk
Address :
12345xxxxxxxxxxxxxxxxxxxxxxxxx
Signature :
H3fsdgagdfghHtgansdf.....=