It is a 10% dividend tax that has to be retained by the company on disbursement of the dividend. Hence, when you receive the dividend, you pay the additional 30%, or whatever your tax band required. Pension funds could previously reclaim this 10%, however they cannot now do so.
Value of the "tax" is equal to 10% of all dividends in the past 9 years, of company shares held by pension schemes. There are no other payments made that are taxed.
Sikeano - you make no sense and sound like a drunkard. BoNY have nothing to do with it - the tax regime is UK-based, and the matter in question is highly significant.