LWO is an abbreviation of light-weight object and it refers to a new feature introduced in the experimental branch of DGD 1.2 at version 1.2.18. Dworkin described them as follows:
Like clones, they are created from a master object, which is a normal, persistent object. Light-weight objects do have some restrictions:
they cannot be explicitly destruct
they cannot be used as an editor, user or parser object
they cannot have callouts
destruct a master object will also instantly destruct all light-weight objects made therefrom (!)
Furthermore, like arrays, they are local to the dataspace of some particular (persistent) object. This means that if a light-weight object is exported to some other object's dataspace, it will become a <copy> there at the end of the LPC thread, just as currently happens with arrays and mappings.