diff --git a/STL_Extension/doc/STL_Extension/CGAL/Spatial_grid_lock_data_structure_3.h b/STL_Extension/doc/STL_Extension/CGAL/Spatial_grid_lock_data_structure_3.h
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+++ b/STL_Extension/doc/STL_Extension/CGAL/Spatial_grid_lock_data_structure_3.h
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+
+namespace CGAL {
+
+/*!
+\ingroup PkgStlExtension
+
+The class `Spatial_grid_lock_data_structure_3` allows to lock 
+point coordinates (x, y, z) in a 3D grid. For example, it can be used by 
+concurrent algorithms to lock simplices.
+
+\tparam Grid_lock_tag allows to choose the locking strategy used by the
+structure. The following tags are available:
+- `Tag_non_blocking_with_atomics` is non-blocking (i.e. trye_lock will always
+return immediately) and uses atomics to perform lock operations.
+- `Tag_non_blocking_with_mutexes` is non-blocking (i.e. trye_lock will always
+return immediately) and uses mutexes to perform lock operations.
+- `Tag_priority_blocking_with_atomics` provides both non-blocking and
+partially-locking `try_lock` versions. The partially-locking version will 
+block/spin if the thread owning the lock has a "lower ID" (each threads is 
+given an arbitrary ID) or return immediately otherwise. It uses atomics to 
+perform lock operations.
+
+\cgalModels `SpatialLockDataStructure_3`
+*/
+
+template <typename Grid_lock_tag>
+class Spatial_grid_lock_data_structure_3
+{
+public:
+
+/// \name Creation
+/// @{
+
+/// Construct the lock grid of size `bbox`, with `num_grid_cells_per_axis` 
+/// cells per axis.
+Spatial_grid_lock_data_structure_3(const Bbox_3 &bbox,
+                                   int num_grid_cells_per_axis);
+
+/// @}
+
+}; /* end Spatial_grid_lock_data_structure_3 */
+} /* end namespace CGAL */