Canon D20 - Manual (Page 174)

Using Optional Accessories
174
You can switch to the shoulder strap or carabiner strap to suit the conditions
of camera use.
Switching to the Shoulder Strap
Attach the strap mount.
Follow the steps on p. 15 to remove the strap
mount included with the camera and attach
the shoulder strap mount.
Attach the smaller fastener to the
camera.
Attach the smaller shoulder strap fastener to
the camera as shown.
Changing Straps