What do the letters and numbers mean in file names such as PA260001.jpg?
The first letter P stands for picture.
The second to fourth number/letter represents the date the image is taken. The second number/letter represent month (1-9 for Jan-Sep, ABC for Oct-Dec). The third and fourth number represent day. For example, 103 means Jan 3rd and B23 means Nov 23rd.
The fifth to the eighth number represent the file number. Max is 9999.