HP LaserJet Enterprise 500 MFP M525 - Manual (Page 53)

Print when a toner cartridge is at estimated end of
life
<Supply> Low This message displays when a supply is nearing the estimated
end of its useful life.
<Supply> Very Low This message displays when a supply is at its estimated end of
useful life. Print-quality problems can occur when using a
supply that is at its estimated end of life.
ENWW Print when a toner cartridge is at estimated end of life 39