Diff Merge enables you to compare up to 16 contributors at a time (where a contributor is a single file, directory, or version).
Diff Merge selects one of the contributors to be the base contributor, which is the contributor against which all other contributors are compared. Wherever a contributor differs from the base contributor, Diff Merge marks that difference graphically. (For details about the ClearCase file and directory comparison algorithms, see the diff and cleardiff pages in Command Reference.)
Each contributor appears in a separate pane in the display, with the base contributor appearing as the left most or the topmost contributor, depending on how the panes are arranged.