[capink]

• You can have nested sub-menus by using ::: as a separator in the submenus field e.g. submenu1:::submenu2:::submenu3
• You can hide chain menu entries by putting the chain in a submenu called "Invisible".
• If you don't want the submenu to have the same icon as the first child entry, set the following tweak in calibre preferences > tweaks > plugin tweaks.
  

  action_chains_default_sub_menu_icon = False

• If you want to change the submenu for multiple chains at once, select the entries to the chains in the Add/Modify chains dialog > make sure the active cell is the submenu cell (on any of the selected entries) > press F2 > a pop-up input dialog will appear where you can enter the new submenu name.
• Increment numerical column using a template.
• Conditionaly update a tag-like column using a template.
• Change calibre double click behavior using the event: Library View Double Clicked
• Save and restore book selection during any point in the lifetime of the chain
• Select a subset of selected books based on criteria