Tell me the origins of search engine conventions

Factual Questions
1

There are many conventions for search engines, like

Putting double quotes around phrases.
Capitals being case sensitive but lower case not.
Hi, Opal!
The + and - signs denoting mandatory and mandatory not.
And so on.

But when and where did they originate?

2

These two at least go back to DIALOG searching, one of the biggest online search tools. DIALOG goes back to the 1960s, I don’t know if those conventions do.