ACK： Acknowledge
Adv. Advertised (a register classification tag)
AIS：Alarm Indication Signal
AOC：Active Optical Cable
ASCII American Standard Code for Information Interchange (the numerical representation of a character)
BER：Bit Error Ratio (dimensionless) or Bit Error Rate (per unit time)
BERT：BER Testing
BOL：Begin of Life
CDB：Command Data Block
CDM：Code Division Multiplex
CDR：Clock and Data Recovery
CLEI：Common Language Equipment Identification
CMIS：Common Management Interface Specification
Cnd. Conditionally required (a register classification tag)
COR：Clear on Read (side effect)
CTLE：Continuous Time Linear Equalizer
CWDM：Coarse Wavelength Division Multiplexing
DFB：Distributed Feedback Laser
DPSM：Data Path State Machine
DWDM： Dense Wavelength Division Multiplexing
EC： Explicit Control (name of a control bit)
EML：Externally Modulated Laser
EPL：Extended Payload
ePPS enhanced Pulse Per Second (a timing signal) 29
EOL：End of Life
FC Fibre Channel
FEC：Forward Error Correction
FERC：Frame Error Count
FP：Fabry-Perot (a laser type)
FSM：Finite State Machine
HP： Host Path
IA ：Implementation Agreement 37
IB ：InfiniBand
IC ：Integrated Circuit
ID： Identifier
ISI： Inter-Symbol Interference
I2C： Inter IC (a two-wire bus specification)
I2CMCI： I2C-based MCI (a management communication interface specification defined here)
LF： Local Fault
LOL： Loss of Lock
LOS Loss of Signal
LPL ：Local Payload
LSB Least Significant Bit (in a multiple bits context), Least Significant Byte (in a multi-byte context)
LTP： Level Transition Parameters
MBR ：Module Boot Record
MCI ：Management Communication Interface
MIS： Management Interface Specification
MSB： Most Significant Bit (in a multiple bits context), Most Significant Byte (in a multi-byte context)
MSL： Management Signaling Layer
MSM ：Module State Machine
N/A ：Not Applicable or Not Available 56
NACK ：Not Acknowledged
NP：Network Path
NPSM： Network Path State Machine
NV ：Non-Volatile 1
OIF ：Optical Internetworking Forum
OMA ：Optical Modulation Amplitude
OOR： Out of Range
Opt. Optional (register classification)
OTN ：Optical Transport Network
OUI ：Organizationally Unique Identifier (unique vendor code assigned by the IEEE)
PM：Performance Monitoring
PRBS： Pseudo Random Binary Sequence （伪随机二进制序列）
PSL ：Pattern Synchronization Loss
RO ：Read-Only
RAL ：Register Access Layer
RF ：Remote Fault
Rqd. Required (a register classification tag)
RW： Readable and Writeable
Rx Receiver function of module, receive direction (media to host)
SC ：Self-Clearing (side effect)
SI ：Signal Integrity
SCL ：unidirectional Serial Clock
SDA： bidirectional Serial Data
SM： State Machine
SFF： Small Form Factor
STD： State Transition Diagram
STT State Transition Table
TC：Threshold Crossing
TDM Time Division Multiplex
TEC Thermoelectric Cooler
TWI Two Wire Interface (an obsolescent alias for I2C)
Tx Transmitter function of module, transmit direction (host to media)
VCSEL：Vertical Cavity Surface Emitting Laser
VDM： Versatile Diagnostics Monitoring
WDM：Wavelength Division Multiplexing
WO：Write-Only