Nikon D300 Complete Manual page 498

5. Images are displayed six at a time:
6. Pressing the center of the Direction pad selects or
deselects image(s) for deletion (you'll see the p icon
appear on it (see image 100-25, below).
If you need to see the image better in order to
determine if this is one you want to delete, press the
Zoom In (h) button.
7. Press the OK button to get the confirmation prompt.
Use the Direction pad to navigate to Yes and press
the OK button again to confirm the deletion.
The two choices in the Delete Menu Item are:
Thom Hogan's Complete Guide to the Nikon D300
V1.02
Page 498