Capacitor notation number multiplied by number in circuit diagram (22x16)
What is 22x16 (10x10)? (it's not the size).


In this case, it is (as suggested by Peter Smith in a comment): capacitance value "x" rated voltage

For example, see this example on Rodar Electronica's website of "22x16" (see green boxes):







And here is another random example, this time a listing from this website, describing a capacitor of 47uF 100V as "47x100":







In my experience, this notation seems to be used more in some parts of the world than others.

However beware, because sometimes that notation of "number x number" can refer to the capacitor's size. Here is an example where "10x16" in the description means a diameter of 10mm and 16mm tall and does not refer to the capacitor value and rated voltage: