insert (thing)

Keyboard command key, located (on a standard 102 key keyboard) above delete, and to the left of home.
Clustered with 5 other keys: delete, home, end, page up, and page down; Between the alphanumeric keypad, the numeric keypad, and under the print screen, scroll lock, and pause keys.

Also accessible from the numeric keypad by disabling Num-lock, or with shift key combinations.