Asking to add a signal code for the 'NOTE'(or INFO equivalent).
For example,
to log ERROR, do SIGNAL SQLSTATE '45000';
to log WARNING, do SIGNAL SQLSTATE '01000';
But there is no normal log siognal code.
So that,

• Request a signal code for NOTE or INFO which is not and error kind.
  e.g) SIGNAL STATE '00000' set message ='sample.'

it makes people/db enginer recognize the exact timing between another system logs.
Without that, we need to compare with custom user table log system and error.log manuall.y