Interpreting a voltage requirement given both as a range and as a percentage?
It's hard to tell exactly what the author of the datasheet of this err... classic¹ printer meant, but my interpretation:

Any grid voltage between 100 and 127 V is OK, as long as it doesn't fluctuate more than +- 10 %, and has a frequency of either 50 or 60 Hz, with a frequency tolerance of 3%.


¹ wow, 22W standby... that's somewhere in the 1 to 4 W range for modern laser printers. If you plan to use that printer: do a yearly power usage calculation to make sure you're not effectively paying more in electricity for your old printer than you'd pay for a new one. For example, assuming the thing is in standby 97% of a year, and it uses 20W more than a modern printer, and a price of 30ct/kWh, that's pretty much 50€ you're converting to nothing a year more. Might be worth investing 80€ in a new laser printer, even if toner is slightly more expensive, especially because printers really got faster and better in the last 20 years.