style and xml

src/framework/core/ParticleClassNames.xml

 <chapter name="Particle Names">
 
   <!-- For selected particles it is possible to specify the C++ class
-       names for a specific unique PDG code -->
+       names "classname" for a specific unique PDG codes
+       
+       This overwrites the default from Pythia8 ParticleData.xml
+
+       If needed, also the text-output form for particles 
+       can be changed using "name"
+        -->
   
   <particle pdgID="0" classname="Unknown"/> <!-- VOID in Pythia8 -->
   
   <particle pdgID="11" classname="Electron"/>
   <particle pdgID="-11" classname="Positron"/>
-  <particle pdgID="22" classname="Photon"/>
+  <particle pdgID="22" classname="Photon" name="photon"/>
 
   <particle pdgID="130" classname="K0Long"/>
   <particle pdgID="310" classname="K0Short"/>