I could not find any documentation of the field important_content.
What is the purpose of this field?
It gets the value from H1-H3 tags ("//*[self::H1 or self::H2 or self::H3]), but why it’s boost values are negative?
A negative value disables the feature. So, it’s disabled by default.
So if I put some positive values there, then document should have boost if search criteria hits the important_content field? Anything else I should make?
Yes, the important_content field affects a score.
Is it possible to define boost value for additional field?
So if I define a new indexed additional field, is there any way to define boost value for this field?
To define own scoring, you can set ScoreFunctionBuilder to QueryHelper.