IBM DS8900F Introduction And Planning Manual page 152

CAUTION: Data processing environments can contain equipment transmitting on system links
with laser modules that operate at greater than Class 1 power levels. For this reason, never look
into the end of an optical fiber cable or open receptacle. Although shining light into one end and
looking into the other end of a disconnected optical fiber to verify the continuity of optic fibers may
not injure the eye, this procedure is potentially dangerous. Therefore, verifying the continuity of
optical fibers by shining light into one end and looking at the other end is not recommended. To
verify continuity of a fiber optic cable, use an optical light source and power meter. (C027)
138 IBM DS8900F: DS8900F Introduction and Planning Guide