These small radish spots mark forms inherited from other forms. If you right click a node with this spot you can find in context menu additional “Select parent” menu item. If you click on this item, Sisulizer navigates you to parent form of selected inherited form node. If you like to see full hierarchical structure of inherited and parent forms in project tree, simply open your Delphi source properties (via source context menu in Project tree or via “Project” menu > “Edit source”), go to “VCL options” tab and check “Scan inherited forms hierarchically” checkbox.
Here screenshot with unchecked this option:
…and with checked this option:
Applying these changes require using “Scan for changes” feature. However, it won’t influence scan/build results.
Small warning icon could be added to form icon in project tree when Sisulizer after changes in source files will find unused inherited form that is not linked to the application. The dialog is most liked unused but still remain in the project file. Remove the unit from the project file (DPR).