Zchloty

A mention in The Colour of Magic says: 'he selected a Zchloty' leaden quarter-iotum'. This suggests that the iotum is very low-value coin from an otherwise unknown domain called Zlocht or Zlochty.
The Discworld Companion states that Zchloty is actually a region, and that the corresponding currency is the iotum (pl. iota).

Annotation

Possibly related to Roundworld's Poland, whose unit of coinage is the zloty? Is this the currency used in Sto Lat?