Nintendo Entertainment System:

To differentiate Nintendo's new home platform from the early 1980s' common perception of a troubled and shallow video game market, the company freshened its product nomenclature and positioning, and it established a strict product approval and licensing policy. The overall system was referred to as an "Entertainment System" instead of a "video game system", which was centered upon a machine called a "Control Deck" instead of a "console", and which featured software cartridges called "Game Paks" instead of "video games". The 10NES lockout chip system acted as a lock-and-key coupling of each Game Pak and Control Deck, deterring the copying or production of NES games which had not first achieved Nintendo's licensed approval. The packaging of the launch lineup of NES games bore pictures of a very close representation of the actual onscreen graphics of the game, which were of sufficiently recognizable quality on their own. Symbols on the launch games' packaging clearly indicated the genre of the game, in order to reduce consumer confusion. A 'seal of quality' was printed on all appropriately licensed game and accessory packaging. The initial seal stated, "This seal is your assurance that Nintendo has approved and guaranteed the quality of this product". This text was later changed to "Official Nintendo Seal of Quality".

Please answer a question about this article. If the question is unanswerable, say "unanswerable". What was printed on all licensed games and accessories by Nintendo?
seal of quality