When all other entities are created, they are assigned unique IDs by the system that are also fixed for the lifetime of the entities. These are of the form class-xxxx. The second part (referred to as "xxxx") consists of 24 case-sensitive characters from 0123456789BFGJKPQVXYZbfgjkpqvxyz, e.g.: project-j47b1k3z8Jqqv001213v312j1, or file-47jK67093475061g3v95369p. Note that when a data object is copied from one data container to another, its ID remains the same even though its metadata may change in the different data containers in which it resides.