what is the Purpose of creating <C:kerning> in text file before loading in to the indesign file

Question

I have the perl script which converts group of xml in to text file and later it would be coded or formatted to import the text file in to indesign. So the output of the text file has some indesign tags that includes <para:body>,<para:text>,<chatacter:style> and other tags. I understand these are meant to meet the minimal requirements to import the design file and keep the format. However, I am not understanding the purpose of the tag called <C:kerning> in the output text file. Can some one please explain the <C:kerning> tag importance? Is it really required or adobe indesign has the built in feature to do the kerning automatically?