Yes, must remember "Engage Brain before engaging mouth" :-)

The only problem area with sys(2015) on a network is if the system clocks are not synchronised and then there is a v. small chance that duplicate UID's could be generated. I like your idea of the prefix. Because it always starts with an underscore, you could replace that with a chr() val which would give 255 unique workstations and also a means of logging 'who dun it'!