1820–30; contr. of and per se and lit., (the symbol) & by itself (stands for) and; see per se

For this part I'm with you Jackie. It's abacadabra, the Latin is confusing. The history of the sign is interesting though.

btw. The thing called octothorpe here # is on our phones and all automatic answering machines tell us: "and/or close with a "little fence" ". Small countries use small words.