Hi,
the cr attribute 'type' differentiates between incidents, problems and requests. Type='I' for Incidents, 'R' for Requests, 'P' for Problems. There are also specific 'factories' (effectively sub-classes of 'cr'): 'in' presents only Incidents and 'pr' presents only Problem records, but the factory (or class) 'cr' presents Incidents, Problems and Requests. You can see the factory definitions in bopcfg\majic\cm.maj.
If you want to launch a macro only for requests then you can put a filter in the trigger that launches it. What are you trying to do?
Regards,
James