Clearly, a depositor can only define and redefine their own Depositor defined IDs, and clearly, a depositor can only use another source’s *IDX if it is already defined in ChEMBL. Although allowing the use of *IDX’s from other depositors creates great flexibility in the data model, depositors should be made very aware of the potential dangers of doing this, since a *IDX used in this way cannot be edited by them, and indeed may be edited by the real owner at any time, without notifying anyone. Depositing against other depositors *IDX’s should therefore ONLY be done in cases where the depositor is very confident in the ability of the other depositor to maintain their *IDX’s correctly.