The user can ``tag'' each individual message with a profile. This is in essence a set of properties which accompany a given message, and give information about the source (origin), type of message, and severity of the message. The number of such properties is not hard-coded, although three properties and a name are the adopted standard in PHENIX. A message without an explicit profile will get a default one which the user can specify globally.

So for a given message, the source could be the event builder, the type a run-time message, and the severity ``warning''. It is useful to distinguish run-time messages such as ``Could not open file'' from another category ``code debug'', which tells about genuine bugs in the code (such as ``division by 0'').

The standard system comes with a set of somewhat arbitrary categories. These are not hard-coded, in fact, they could be different on an application by application basis.