What will i use to achieve this, is it Catalog client script or Catalog UI Policy?

I need help to modify and add to this script for the banner to display in RED and bold on top of the catalog item form.  function onLoad() {    g_form.addInfoMessage('**Submission does not guarantee the request will be approved!**', 'danger');}

Please I need help to write a script include  that will filter CIs to some classes in INC form. classes includes: ApplicationBusiness ServiceBusiness ApplicationBusiness capabilityHardwareStorage DeviceVoice System Hardware.   the Idea is that we do ...