...
- exploratory runs were made (for climate or performance) and that commit was not already tagged on a permanent branch (see below).
- where speculative code development was performed, not merged into master, but needs to be retained
- Some journals requires the precise code used in the published simulations be available publicly. Simulations made during the development process may be using code that doesn't have an official tag like "acmev1-beta01", and one can create an archive tag to identify this version. Archival tags will publicly accessible in ACME public releases.
(See /wiki/spaces/SE/pages/4718815 for discussion that articulated this use case.
...