Continuous memory

The term continuous memory was used by HP calculators to indicate that the calculator can preserve it's memory contents even if the power was turned off. Before the HP-25C (first HP calculator with this feature) calculators lost all memory contents when turned off. HP-25C and HP-29C calculators had the words "Continuous Memory" printed on them with script blue letters. After those models this feature becomes standard in new HP calculator models so the use of these words was discontinued, although several later models preserve the C letter in their designations.