The /PC01 fare designator and the rule restriction would imply this is a private fare, intended only for sale to specific UA account codes (specific customers of United). The website has a lot of integration with corporate accounts these days; if your profile is linked to one in any fashion, it could be pulling a fare or a "personal" version of the fare (there's a thread on getting discounts for being an employee of a customer). Note that while usually a fare with -N in eighth position is non-refundable, but that the fare designator will usually include one or more template overrides. The base fare BAA0AFFN will be a non-refundable C fare, but the private could be refundable (or it could not). The key text you want is "CANCELLATIONS PERMITTED" in Cat16, which no additional fee.