Eliot, The best place to start for understanding what all the acronyms mean would be the Bluetooth specification. You can find that at www.bluetooth.org. The specific specs you will be interested in are the 1.1 Core Specification (L2CAP, RFCOMM, SDP, UUID) or the Profiles specification (OBEX). In addition some of the newer Profile specifications have their own copies outside of the larger Profiles document mentioned above. You would be interested in the HID specification for how HID works. Could someone please explain what some of the different abbreviations mean that are used so frequently in the header files? (L2CAP, OBEX, RFCOMM, SDP, UUID, any others that I should know about...) A quick glossary: L2CAP - Logical Link Control Adaptation Protocol - This is the basic data channel used for Bluetooth communications. SDP - Service Discovery Profile - This is the profile used to discover which services are available on a device. UUID - Universally Unique ID - A 128 bit unique value to ID different service types. There are 16 bit and 32 bit short versions of common 128 bit UUIDs (like OBEX Object Push, Serial Port, etc.) RFCOMM - I cannot remember what that stands for, but it is a serial port emulation layer over an RF link. This is heavily borrowed from an ETSI (European Standards group) specification which you can get from www.etsi.org. Good news is that you will not need this unless you are emulating a serial port which the HID stuff does not do. In addition the HID specification borrows heavily from the USB HID specification, so you will probably need to download some specifications from www.usb.org to understand the HID formats of the data returned on the L2CAP channels. Your code also opens up one of the HID channels. You may want to try opening the Interrupt channel: kBluetoothL2CAPPSMHIDInterrupt. I am not sure, but I believe all the HID data comes on the interrupt channel, and configuration happens on the control channel. The HID specification should clarify all this. -larson _______________________________________________ bluetooth-dev mailing list | bluetooth-dev@lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/bluetooth-dev Do not post admin requests to the list. They will be ignored.