C1Splitter has designer verbs displayed in the shortcut menu or context menu associated with the C1Splitter and C1UpdateSplitter controls.

C1Splitter Context Menu
Right-click anywhere on the C1Splitter control to display its context menu.

The following command has been added to this context menu by Splitter for ASP.NET Web Forms:

Show Smart Tag

Click Show Smart Tag to open the C1Splitter Tasks menu.