J,
Shal, didn't the use come about via hash functions, used to speed
searches in a DBMS?
I don't think Wikipedia mentioned that, nor have I heard that explanation.
I was amused that Wikipedia cited PDP-11 assembly language for use of # as the Immediate specifier on instruction operands. They cited it as an example of using number sign as a marker to alter the meaning of what follows, they didn't relate it specifically to the social media usage.
... I remember hash functions and just assumed that when hashtags
came into their own in social media, they were related to them.
Both are used to index information, so I can sort of see that.
But I think the word "hash" had been associated with the number sign independently, and became a convenient name for the usage. It rolls off the tongue more readily than #number-sign-tag, or #octothorptag. Maybe #poundtag would have worked (too overloaded with meaning?).
Shal
Shal Farley