[GreenKeys] Why has the '#' symbol been called a number sign, pound sign, and now 'hashtag'?

[Dave Horsfall]

On Sun, 11 Jun 2017, Alf Fisher wrote:

> Those that did computer programming like Fortran? might have come across 
> it as some kind of special operator. like @# - No doubt someone more 
> computer literate than me can explain what it does.

Haven't seen that in Fortran; then again, the last time I used Fortran 
would be the early 70s.  I thought it might be a Perl operator, but after 
checking it doesn't seem to be.

-- 
Dave Horsfall DTM (VK2KFU)  "Those who don't understand security will suffer."