UNSPSC

UNSPSC is a hierarchical global taxonomy: segment, family, class, then commodity. Canadian federal procurement uses it in parallel with GSIN, and many other jurisdictions and private buyers use it too.

Because the hierarchy has several levels, choosing the right depth matters. Register at too high a level and you receive everything in a broad segment; too low and you miss adjacent work you could deliver. Most suppliers land on class level as the practical compromise.