1. According to the late MW Cooper, Project GARNET is the project responsible for the control of all information and documents regarding UFOs and the presence of aliens on earth. It is also responsible for the accountability of the information and documents.
Other sources, too, refer to project Garnet as a project to collect all possible information with regard to UFOs and the presence of aliens on Earth. This includes the information gathered by UFO researchers, as well as by other organisations (in other countries).
Source: MW Cooper. Reliability: uncertain.
2. Another source, however, claims that Project Garnet's purpose was to investigate the influence of extraterrestrials on human affairs and evolution. It would have been closed down, supposedly, on completion of its studies.
Source = document posted anonymously on a Compuserve forum in the early 90s. Reliability: unknown.
Note: if this source is correct then the collection of information (= what others say project Garnet is about) would be a necessary phase of the project.