Sentence:  Wat imagines he is asked for thirty <WSD>pennies sterling</WSD> (two and a half shillings), when he is really being asked for thirty pennies Scots (two and a half <WSD>pennies sterling</WSD>). 
Meaning of the word marked with <WSD> tags:  A British coin worth 1⁄240 of a pound sterling, made of silver prior to 1496, and copper thereafter, Abbreviation: d.