Is CCC marking required on power banks when flying through China?

They are watching CCC, in Beijing they took it without this sign from me

In Shanghai, they were indifferent to the power bank labeling..just showed what they had and that's it

Today we were in Beijing, we didn't look at the labels at all

It is not allowed to use in the airplane, they ask to turn off...Chinese airlines

I flew to Seoul and from Seoul with a layover in Beijing, international flights. In the first case, the layover was 4 hours, in the second case it was lengthy - I went through border control, stayed overnight in the transit hotel. I did not have any issues with the customs declaration. In the first case, they did not even look at the bank at all, in the second case they looked carefully and put it back. I think they are not looking at this labeling.