"Also Known As" for stock types

[sde1000]

It would be useful to have an additional column for Stock Types which contains text. This would not be an official part of the stock type (no uniqueness constraint), and wouldn't be displayed on the till, but would be included in stock type searches.

For example, we sell cider from Gwynt y Ddraig so that's what goes in the Manufacturer column. Invoices we get have this as "GYD", but searching for "GYD" does not currently show any of the correct stock types.