On this search page:
https://help.quicken.com/dosearchsite.action
Pressing the round ? button next to the search box brings up information on search syntax that looks as follows:
Exact phrase search
To search for content that contains the exact phrase "chalk and cheese":
"chalk and cheese"
OR search
To search for content that contains one of the terms, "chalk" OR "cheese":
"chalk OR cheese"
AND search
To search for content that contains both the terms "chalk" AND "cheese":
"chalk AND cheese"
…
The first one is correct, but the second two (and possibly others) are incorrect. Each search term should be quoted like this:
OR search
To search for content that contains one of the terms, "chalk" OR "cheese":
"chalk" OR "cheese"
AND search
To search for content that contains both the terms "chalk" AND "cheese":
"chalk" AND "cheese"