1. A quality management system for products comprising: a multiplicity of product unit specific indicators each operative to provide a machine-readable indication of exceedence of at least one threshold by at least one product quality determining parameter, said machine-readable indication comprising a variable bar code having a first readable state and at least a second readable state, each readable state including digital indicia and at least start and stop code indicia, at least two digital indicia being different between said second readable state and said first readable state; an indicator reader operative to read said product unit specific indicators and to provide output indications; and a product type specific indication interpreter operative to receive said output indications and to provide human sensible, product unit specific, product quality status outputs.