Dennis -- Your reply reminded me of one other reason I name files this way. I went from a D1X, to a single D100, to a single D200, then a single D700. I frankly didn't think I would have two or more bodies until after I retired from government work and started shooting more professional stuff. One day as I was in the middle of the Mississippi River shooting a tow boat for several hours for a barge company, while $15 million dollars of cargo lay waiting tied up to the shore, it suddenly dawned on me that this would be my first and LAST job for them if my relatively new D700 crapped out. So the next day I ordered a second D700 body. I didn't need to differentiate between images shot with more than one body until then, but this allows me to quickly identify where a problem lies if one crops up and prevents identical file numbers from cropping up accidentally. You just never know when you are going to decide you need to add a 2nd or 3rd body. This ensures you are ready. You can put your initials, your name or your copyright in the comments area.