Boolean Search Operators
Implement advanced boolean operators, with all the normal operators (AND, OR, XOR, NEAR, NOT, and exact phrase match) and parenthesis support for precedence.
Should search in titles, note's contents and hopefully in the indexed attachment contents.
I saw that the vulcan web client supports this but as far as I know it only searches for titles and labels and attachments' titles.

Search in the web client and desktop now use the same underlying technology. Both web and desktop index all text associated with a thought including content within most attached files. Both web and desktop support boolean operators. We are working on updating the documentation - a slightly out of date version can be found here: https://bra.in/4jYgwA