A pencil at an angle, opening something for editing.
A pencil drawn on a diagonal marks the control that puts an item into an editable state. It is one of the few interface icons whose metaphor has not drifted at all since it appeared.
Puts the item it is attached to into a state where its content can be changed.
Contexts: Software
A long narrow body set on a diagonal, tapering at its lower end to a short point, with a squared-off end at the top.
Both are built from objects, and both are used in software contexts.