The latter usage is rare outside North America. The sign is not used to denote pounds as weight ( or is used for this), and certainly not for pounds currency. The use of as an abbreviation for "number" is however common in informal writing, but use in print is rare. Where Americans might write "Symphony #5", British and Irish people are more likely to write "Symphony No. 5". British typewriters had a key where American typewriters had a key. Many computer and teleprinter codes (such as BS 4730 (the UK national variant of the ISO/IEC 646 character set) substituted '£' for '#' to make the British versions, thus it was common for the same binary code to display as on US equipment and on British equipment. ('$' was not substituted due to obvious problems if an attempt was made to communicate monetary values).