It's a witty piece that could be said to examine the play through the lens of modern day taxation. The document itself appears to have been written by Hamish McTax, Royal Counsellor, Tax Adviser to Royalty.
Apparently "scribbled on the back of the document was this chilling rhyme:"
Double, double, VAT is trouble,
ATED burn and FATCA bubble.
Number of a DOTAS scheme,
Echo of a non-dom's scream.
partner's notice, APN,
Payment with a stroke of pen.
Film investment, foreign trust,
years of planning, turned to dust.
For a charm of taxing trouble,
Like a hell-broth, boil and bubble.
Nice one, Sarah