I think the ST (dated 2007) might refer to a scheme in the UK where an employee could donate a percentage of his/her salary/wages to a registered charity. Such donations were considered as part of the employee's income, and the corresponding “pretax” was mentioned on the payslip. However, the charity could then declare the received donation to the tax authority, who would then transfer (all or part of) the “pretax” to the charity, as a “bonus” on top of the employee’s donation.

I don’t think the scheme has survived recent UK government legislation, but a (vaguely) similar scheme (applying to ordinary charity donations, perhaps not to amounts taken from wages/salary) is mentioned here, in Jersey (Channel Islands), which is a dependency of the British Crown (and well-known haven for folk allergic to paying tax):

http://jerseywomensrefuge.org/help-us/donate/

“If you are a Jersey resident and pay tax, your donation may be eligible for tax exemption. If you have made a one-off payment of £50 or over, the lump sum donation scheme the charity gets an additional 25%. So if you donate £100 the charity will get an additional £25.
Please complete and return the R10 Certificate to our Administrator at PO Box 708, St Helier, Jersey, JE4 0PW, and we will be able to increase the amount of your gift by reclaiming the tax due on the amount.”

(NB: there's a word mising in the website: "... £50 or over, the lump sum donation scheme ..." should read: "... £50 or over, under the lump sum donation scheme...".)