Do Not Vendor - Marks items you don't want to vendor with red and white slash
Bank Example

Bank Example

This shows the DoNotVendor red and white slash in the bank.
Bag Example

Bag Example

This shows the DoNotVendor red and white slash in some bags.
Character pane example

Character pane example

This shows the DoNotVendor red and white slash in the character pane.
Minimap

Minimap

This shows the tooltip when you hover over the DoNotVendor minimap button.