Final answer:
The ISO/IEC 11810 uses the acronym OM (Optical Multimode) to describe multimode optical fiber, with different levels such as OM1, OM2, OM3, and OM4 signifying varying performance standards.
Step-by-step explanation:
The acronym that the ISO/IEC 11810 uses to describe multimode optical fiber is OM. The 'OM' stands for Optical Multimode, and it is a part of a series of standards that classify the performance of multimode fibers. ISO/IEC has several specifications for multimode fibers like OM1, OM2, OM3, and OM4, with each specification denoting a different level of performance. These classifications help in understanding the capabilities of optical fibers, including factors such as modal bandwidth and maximum distance for various data rates.