Why the disparity? And why use 'No.'? Is it from the French?
And the hash or pound sign seems a weird choice too, is there a history or any reason involved?
No. comes from the abbreviation of "numero", ablative case of the Latin "numerus"
The reason the # wasn't used as a numbering sign in England was because the pound in England was denoted by the (£) sign, so
1 The above was taken from here
I consider this etymology to be more correct for
I couldn't find anything on the # symbol yet, I guess that wikipedia article is the only source. I'll make sure to edit in case I find something else.
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