I would appreciate hearing from anyone who uses Digital Pro 4 to provide helpful tips. Comparisons with competing programs are also welcome because they provide helpful perspective. Anyone with questions about the program should please feel free to ask them in this thread. I'll begin with the first question, which requires some background information. I'm a first-time user still on the 30-day trial period. My primary interest is being able to sort on metadata. Using DP4's powerful search mechanism that can be limited to a particular folder or not, I can sort on categories, subcategories and keywords. That total solution is not possible using Nikon software. I'm concerned that Nikon doesn't publish the vital information in the developers' tool kit about the exact use of XMP data fields. (I am making a distinction between EXIF, XMP and IPTC data.) Metadata applied to them today by non-Nikon programs might adversely affect the file if Nikon changes something about its use of those fields in the future. In fact, Tomas provided in a separate thread an email from a developer of a competing program about that risk with regard to all such third-party products. One main reason I have selected DP4 is that it writes XMP data either to the sidecar file or to the NEF at the user's option, as opposed to Photo Mechanic which apparently writes only to a sidecar file. (Many thanks to Bill for making me aware of that, which is what got me interested in DP4.) EDIT: Thanks to Micky and Pesto for pointing out that apparently Photo Mechanic does indeed write to either the NEF or the sidecar file at the user's discretion. One solution I'm considering is applying all metadata using DP4 as the very last step in my combined post-processing, image-management workflow. I would have two versions of each image, one with the XMP data applied to the sidecar file and one with it applied to the NEF. I don't mind the commitment to the storage space that would be required. I'm also considering applying all metadata using Nikon products and using DP4 to read and sort on that data. Using that method, I would not be able to read Nikon's stars or labels but I would only have to save one copy of the NEF. Finally, my questions: Am I thinking this through properly? Do you folks have any additional ideas?