Indicates the current revision for the current design, and allows you to specify a different revision as the current revision. A revision is a group of settings and assignments for the design files in a design. You can use different revisions to determine how different settings and assignments affect the results of processing the design. You can create new revisions, delete existing revisions, compare revisions, and customize columns. You can edit revision descriptions by double-clicking inside Description box, which is saved in the revision description file Definition generated for the revision.