What are "Tax Relief Fees" on American Depositary Receipt (ADR) dividends?

I noticed that a "Tax Relief Fee" is usually deducted from ADR dividends. Consider AXA ADR’s (OTC: AXAHY) 2020 cash dividend announcement, which includes a "Tax Relief Fee" of $0.005 per share:

Also consider Sony ADR’s (NYSE: SNE) 2020 semi-annual dividend announcement:

So here we have a clue:

Tax Relief at Source Processing Fee is for Tax Certification Filing

But what does this mean exactly? In particular, I would like to know:

• Who charges this fee? Is it the ADR’s depositary bank, or the Depository Trust Company (DTC)?
• What is this fee used for? What is "Tax Certification Filing"?