HIDmaker takes this a step further, by letting you also give each data item a meaningful name. 

This makes things really easy for you. In addition to making it easy for you to choose a Usage Page / Usage ID combination from the list of predefined Usages, HIDmaker also lets you give your variable a name, lets you specify its size in bits, and set a lot of other properties as well.  (Like for example, is it an array? If so, how many elements are in the array? And so on.)

Then, when HIDmaker generates its code for you, it remembers all those properties, in particular the Usage numbers and the variable name.  The generated code, on both  the peripheral and the Host side, will declare data items with the names that you gave them, which makes it really easy to work with your code.  However, HIDmaker's generated code sends and receives this data in the HID class standard way, identifying each variable by its Usage numbers.