Hi everyone, As I have mentioned in a previous post, I have been trying to learn how to use Boost.Log. I have been experimenting with logging to a file with filtering and specifying the log formatting in three different ways, namely: 1. Specifying the log formatting using a lambda type expression. 2. Specifying the log formatting using a plain text string with placeholders for the attributes that I have defined. 3. Specifying the log formatting in a settings file. (However, the formatting string is exactly the same as in 2 above.) I have attached a copy of my source code and settings file. Note that I comment out parts of the source code file depending on which option I use above. The problem I’m encountering is when I use options 2 & 3 above, the severity level string does not appear in the log. But if I use option 1, the severity level string appears as expected. It is my understanding that severity level is a pre-defined attribute when using a severity_logger. Am I missing something when using options 2 & 3? If I decide to use my own severity level enumeration, what do I need to do? Kind regards, Leo