"Type safe" is both a marketing line and a technical definition. As a technical definition, many languages are type safe (including, say, Ruby) but they achieve

"Type safe" is both a marketing line and a technical definition. As a technical definition, many languages are type safe (including, say, Ruby) but they achieve this by having very low meaning to their (static) types. Typically, the marketing definition means "type safe and expressively typed" which outlaws trivial type systems and their trivial type safety.