You can modify the terminal interface by changing the value associated with a numeric field, adding or deleting a boolean field, or changing the control sequence associated with a string field in an existing vvtermcap entry.
The most likely reasons that you would change an existing vvtermcap field is (1) to reassign the key or key sequences that generate a particular keycode and (2) to change the monochrome or color appearance associated with a physical attribute for that terminal. These procedures are explained here. For other changes, you should refer to your terminal documentation to determine what commands you should use for each mnemonic.
Changing Video Attribute Assignments
