When a trial is re-registered, all known identifiers for the trial should be submitted. These include trial registration Numbers allocated by other registries.

Countries that do not have a well-functioning civil registration system only have approximate ideas of the Numbers, the longevity and the health of their population.

At the bottom of it was a number which looked like one of those serial Numbers you find on the underside of stereo sets which always takes so long to copy on to the registration form.