Actions and constraints on a (section of a) structural component (or a group of structural components) by other structural components or by the environment surrounding it. NOTE Boundary conditions can be used to generate reaction forces at locations of restraint. [ISO 19902:2007, definition 3.6].
Source: ISO 19905-1:202, Petroleum and natural gas industries – Site-specific assessment of mobile offshore units – Part 1: Jack-ups. Global Standards