Ann: September 2012 Quarterly Report , page-5

Not my definition but I ripped the below of HECLA:

Cash Operating Costs – Includes all direct and indirect operating cash costs related directly to the physical activities of producing metals, including mining, processing and other plant costs, third-party refining and marketing expenses and on-site general and administrative costs, net of by-product revenues earned from all metals other than the primary metal produced at each unit.

Basically it doesn't include running the Perth office, exploration, capital expenditure etc.........

More cash required soon cos they're still seriously underwater.