tl;dr USB HID codes from here http://www.freebsddiary.org/APC/usb_hid_usages.php should be given to flirc_util record_api as decimal Hi all Just had to deal with flirc_util record_api on account of the GUI not recognizing the Flirc board as connected (http://forum.flirc.tv/index.php?/topic/2208-linux-x64-flirc_util-works-without-root-but-flirc-gui-always-say-disconnected/#comment-12182 ), and I thought I'd save the information I found in a topic with a descriptive title for future reference: This is also a good resource: http://forum.flirc.tv/index.php?/topic/128-modifier-keys-in-command-line