When the Capture Tool is active and you are capturing or logging clips, Avid takes over your F-Keys. Whatever you have personally mapped there will be replaced by the functions in the list below. While many are aware that when in Capture Mode F4 will begin the capture process, many are not aware that when you are in Logging Mode, F4 will also send a logged clip to the selected bin.
  

F1 – Mark In for Making a Sub Clip while capturing
F2 – Mark Out for Making a Sub Clip while capturing
F3 – Add Red Locator
F4 – Begin Capture when in Capture Mode; Log Clip to bin when in Log Mode.
F5 – Add Red Locator
F6 – Add Green Locator
F7 – Add Blue Locator
F8 – Add Cyan Locator
F9 – Add Magenta Locator
F10 – Add Yellow Locator
F11 – Add Black Locator
F12 – Add White Locator

  
Further, you can map this functionality to any key on your keyboard. Here's where to get that function:
Tools Menu > Command Pallette > Play tab > Record function (see picture below).
NOTE: Don't forget to enable "Button to Button reassignment" to allow you to drag and drop that onto a key.