Type L. Type R. What do they mean? The two types distinguish what approval path you need to follow for labels containing the UL mark. So they are important. But what do those names actually mean? Well, in the end it all comes down to money. Specifically how UL wants to charge you for their follow-up service. The breakdown is as follows:
Type L = Label Charge. Basically you are going to be charged based on the amount of labels you consume. The more labels, the more costs. This also explains the tighter regulations, and why UL needs to know exactly how many labels you are getting. Wire manufacturers typcially fall under this type.
Type R = Review Charge. UL is going to charge you based on a set number of reviews–usually outlined in your Follow-Up Service Procedure documents. Because they aren’t using labels to charge their fees, the approvals process is much easier than Type L. Lighting manufacturers usually fall under this type.