How to disable a letter from being printed?

How do I disable a letter from being printed?

Navigate to General > General Configuration > Configuration Menu > General Configuration > Letter Activity
In the letter type column of the table presented find the row for the letter to have printing disabled
In the right column click the “Customize” button
In the left column click the yellow checkmark
Click “Save”

If the letter appears more than once choose the line which has “EMAIL” in the “Channel” column
Clicking “customize” allows a change
Clicking the yellow checkmark will "ghost" the checkmark, which indicates the letter is no longer active (is disabled)
After making any changes it is advisable to test that the disabled letter is the correct letter
To make the letter printing active again (enabled) click the “Restore” button in the right column of the line for the letter
After doing so the button in the left column will again state “Customize” and the checkmark is again yellow indicating the letter is active (enabled)