The Delete Button should always be used to remove cards from the HyperArchy database. Using the Delete Button will insure that all the linkage fields are updated correctly. Failing to do so will cause failures and glithches.
The Delete Button causes the current card to be deleted, along with all of its Child Cards and all of the Child Cards of its Child Cards (grandchildren), and so on, down to the botom of the hierarchy.
The current card's Parent Card is also told about the deletion by removal of the current card's ID from the Parent Card's "Child IDs" field.