The HC Structural Rearrangements sub-tab (Figure 64) shows the biological classification that can be inferred from one or more entries listed on the HC Structural Variants sub-tab. The GS Reference Mapper software attempts to interpret and classify groups of structural variants in order to assign a higher-level rearrangement type to the group. Summary information about the supporting structural variants is provided on this sub-tab. Right-clicking on a row opens a contextual menu from which one can access the alignment that underlies the variation. Pausing the mouse over a row displays a tooltip providing the classification and either the reference position or the length of the rearrangement. Explanations for each of the columns in the table are found in the description of the 454AllStructRearrangements.txt file, in Section 2.17.1.16.