This video teaches how to save up to 3 different custom function sets on your Canon EOS-1D. Go into the custom function menu, choose the settings you want in each of the custom function sets. Choose "custom function setting register/apply", select register. You will see an overview of which settings you have. Choose to save as Set 1, 2 or 3. Select "OK". You can now go back into the custom functions screen, make whatever changes you wish to the settings, and save as another set. Now you have 3 custom function sets, each appropriate for a different situation. The video then explains how custom sets can also be saved onto memory cards and easily transferred between cameras. From the custom function menu, choose "save settings on media" and save. The card can then be transferred to another camera and the same settings applied by choosing Load. Some settings will not be saved because it could cause problems if you put them in a different camera.