Software projects have a big amount of information associated. That may be irrelevant if we do need just to maintain one development line or branch, but becomes a key to succeed if the product is released to the field and the project is still under active development.
If we want to provide a quality service to the product released to the field we need a photo of all the items that compose the software product and this is not only to put a label in the system we use for keep source code under control.