Missing settings in settings.xml

I noticed the exported settings in settings.cfg and settings.xml are not the same when I export them from the web interface of our D385 phones (same behavior on firmware 10.1.141.13 and 10.1.73.16).

e.g. the setting phone_name is present in settings.cfg and missing in settings.xml

Is this normal? If yes, what is the rationale behind it? I'd expected a full settings export to include all the settings (modulo passwords, of course) in both the cfg and the xml.

Is there a list of the settings that are only included in one of the two files available?

Thanks in advance.