Template:Global securities
In these modern, dematerialised times, the securities in a clearing system — that is, pretty much all securities — exist only as entries in a ledger maintained by the clearing system. The individual securities might not be security-printed, physical things any more, but their origins as such lives on in the “global security”, which is a printed physical thing, on actual paper — usually run off on a word-processor, not security-printed though — which is signed and given to a depositary to hold on the clearing system’s behalf (or on behalf of several clearing systems, in which case it is a “common depositary”).
This global security, representing all notes issued under that ISIN, is technically the instrument the clearing system’s records reflect. On execution of a bond deal, until relatively recent times, a trainee would be sent along with the executed global note to deliver it to the common depositary, a fellow with a green visor, sleeve garters and a permanently malevolent view of humankind, kept in the basement of a building on Queen Victoria Street. He would “authenticate” (counter-sign) it — at which point it would become “live” — and put it in an actual vault where it would gather dust awaiting the time at which holders of the securities it represented might need to converted into actual physical notes again. That time would be the apocalypse, so quite a lot of dust has collected in the meantime.
But this is a detail whose legal significance, in practice, will never affect any practising lawyer, unless the common depositary’s vault is hit by a tactical missile or something, and in that case, even practising lawyers will have plenty else to be worrying about — like packing rifle, tins of spam etc. into a pickup and heading for the hills — so, if they know what is good for them, won’t be consulting the internet at that point to figure out what to do.