TM 10-3930-664-10 1-7. LIST OF ABBREVIATIONS This list consists of special or unique abbreviations, acronyms, or descriptors not contained in MIL-STD-12. Abbreviation Description 4KRTFL 4000 Pound Rough Terrain Forklift ROPS Roll Over Protective Structure FOPS Falling Object Protective Structure 1-8. METRIC UNITS The 4KRTFL described herein contains metric components and requires metric common or special tools; therefore, metric units in addition to English units will be used throughout this publication. 1-2