Hello list,
while using from/p-preferred-identity display names in kamailio.cfg I noticed, that $pn and $fn contain the beginning and ending double quotes ("<display name>") supplied by the UAC.
As those quotes not part of the display name (at least I think so - e.g. they are also not shown by end user devices) I suggest to remove them from $pn and $fn, because otherwise you have to remove them manually with pv transformations/substr, which may takes much more performance...
Best Regards Jasmin