zapata_additional.conf is used by freepbx?

is the file zapata_additional.conf used by freepbx? i noticed that all *_additional.conf file are the ones which generated by freepbx and are included in the *.conf file. but if i’d like to add a pri zap trunk then how can i edit it in freepbx. and if i can’t edit in freepbx why there is a zapata_additional.conf file. or which part of my pri zap trunk should have to put into this config file?
thanks in advance.