*I think, however, that you can preceded mandatory terms with a + sign to requir...

I think, however, that you can preceded mandatory terms with a + sign to require it to be present on page.

That was my first reaction too, but I tried it out and it still doesn't work. In fact, the result is kinda funny:

Googling "webhcat primary key" got me 3 results with "webhcat" on the first page.

Googling "+webhcat primary key" got me 5 results in total, none of which contains the word "webhcat".