libusb – bmRequestType for sending data to an iPhone

I have some code here which is supposedly sending bytes of data to an iPhone using libusb, here’s the offending snippet:

libusb_control_transfer(handle, 0x21, 1, 0, 0, buf, 0x800, 1000);

This works fine but my question here is regarding the second parameter bmRequestType = 0x21, which according to the documentation represents the "request type field for the setup packet". Now, this value is a one byte bitmap , one of the values here is the request type which can be one of the following:

• Standard request type (00)
• Class-specific request type (01)
• Vendor-specific request type (10)

this code is using a class-specific request type, but since this is sending data to my phone, shouldn’t it be using a vendor-specific request type for apple?

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