请教下美国国家公园订宿后额外扣的10%费用是怎

订宿成功后次日收到订购价10%的扣费短信，吓一跳还以为被盗刷了。检查订单邮件发现有个addition条款如下：

In addition: U.S. Park Lodging has charged a 10% non refundable reservation fee based on the total dollar amount of your reservation. This fee is non-refundable but can be transferred for up to 1 year if you need to cancel or change your reservation, and can be used for many different National Parks in the US or Canada. This fee will be billed to your credit card under the memo U.S. Park Lodging.

我理解应该是国家公园另收的。不退但是可以转移就看不懂了。请教下