A Crucible project provides a way to group and manage related reviews – typically reviews that are all involved with the same software project. A Crucible project allows you to Every Crucible review belongs to a project. Each project has a name (e.g. ACME Development) and a key (e.g. ACME). The project key becomes the first part of that project's review keys, e.g. ACME-101, ACME-102, etc: By default, Crucible contains one project. This default project has the key 'CR' and the name 'Default Project'.
See Creating a project.