Here's a list of undocumented features:
Though not specified in the manual, the Time, Hour, and Min buttons have dual functions to aid in tuning and controlling the display. This will not charge batteries internally. You will get stereo FM thru a set of headphones or earbuds, and this is shown in the display when "Stereo" comes up. I do not think there is a way to set it to mono.
With the power off, the Hour key cycles the intensity of the Backlight settings, and you can make the display stay on with the power off. The minutes button toggles the MW tuning steps between 9 and 10 KHz.
In shortwave, the Time button will cycle up thru the SW bands, while the min and hrs buttons act like slewing keys and will either single step 5 KHz up or down on short presses, and will seek on longer presses.
In AM, the time button will act like a step up in frequency button 100 KHz. It will not seek. The min and hrs buttons again act like slewing keys and will step up or down 10 KHz, or a long press for seek, up or down.
In FM, the time button will step up 1 MHz, and the min and hrs buttons are again slewing keys , with steps up/down of 100 KHz and a long press for seek up or down.
Most display are to 2 decimal points, but in shortwave, this extends to 3 decimal points on odd (5) frequencies.