Why is "d" the abbreviation for penny/pence instead of "p"?
Latin
denarius, the coin from which the penny developed. Although the
d was used as the abbreviation for the pre-decimalisation penny, the abbreviation for the current "new" penny in use since 1971 is
p.
Note also that the £ sign is an elaborate
L for
libra - the latin for pound, abbreviated
lb when used for weight. The old currency used to be referred to as "LSD" for "pounds, shillings and pence".