Units
From Protemos Wiki
Go to System => System values => Units.
On this page you can add, update or delete any measurement units you need:
"New unit" – opens the unit creation page where you can create as many measurement units as you need.
"Update" – opens the unit update page. Here you can change the name of the particular unit.
"Delete" – deletes the unit.
Note: you can’t delete units, that you have already used in the project ("Yes" in the column "Іn use" and no "Delete" button).