This is a letter I can support (excerpt):
“The default file naming protocol should include the capture date in this format (YYYYMMDD), followed by a 4-digit number created sequentially from 0001 to 9999. For example, if I format a card in my camera and choose continuous file numbering, the first image on the card that I capture (if my camera is in JPEG mode, and if I take the photo on 9/13/2010) will be 20100913_0001.JPG. If I take the next photo on 9/14/2010, the file name will be 20100914_0002.JPG. It’s important to use continuous file numbering with this approach, or the system will not work when a new card is formatted on the same day as another card. This is the renaming procedure I currently use, and virtually all file renaming software currently provides this renaming functionality.
For all DSLRs (and potentially all other digital cameras), I recommend giving users the ability to designate one or two letters after the YYYYMMDD in case a photographer has multiple cameras, or if the photographer is part of a team of shooters who submits cards for post-processing on a computer that handles multiple photographers’ cards. As long as each camera has a unique letter or letters following the YYYYMMDD, this system will go one step further toward avoiding any duplicate file names (unless more than 26 cameras are involved!). An example of the file name in this case would be 20100913A_0001.JPG, or 20100913AD_0001.JPG.”
The only thing that I would disagree with is this:
“3. Certain countries use YYYYMMDD and others use YYYYDDMM for indicating a specific date. I recommended adding a menu option for either format. Other date formats are commonly used, but I recommend this one because it is compact, easy to read and allows for easy viewing when sorted by file name on a computer or other device. Many cameras already have the ability to choose a specific date and time format.”
YYYYMMDD should _always_ be used – if you use YYYYDDMM (or rather DDMMYYYY in germany) any file list in a window will not be able to be sorted properly, YYYYMMDD is the only way to go.
Instead of using sequential numbers, though, I would suggest using the camera time (HHMMSS).
Including the optional characters, a file name would look like this: YYYYMMDD_HHMMSS_D90.jpg