[For the entire collection see Zbl 0581.00018.]
This paper studies mathematical models of ideal locking solids and locking solids with hysteresis. It is shown that such materials can be studied within the framework of generalized standard materials. Some extremum principles are proposed and interesting open problems are suggested. For perfectly locking behaviour locking limit analysis is formulated and examined. The latter case is illustrated by an example of the torsion of cylindrical bars. The author shows that for perfectly locking solids stresses belong to the space of bounded measures. Several misprints will easily be perceived by the careful reader. The paper reads well and constitutes a valuable contribution to mathematical problems of locking bodies.