The simplest example of a Prefix Query would be something like
f knuth
or
f "donald knuth"
In those queries no attributes was specified.
This leaves it up to the server what fields to search but
most servers will search in all fields. Some servers does not
support this feature though, and require that some attributes
are defined. To add one attribute you could do:
f @attr 1=4 computer
where we search in the title field, since the use(1) is title(4).
If we want to search in the author field and
in the title field, and in the title field using right truncation
it could look something like this:
f @and @attr 1=1003 knuth @attr 1=4 @attr 5=1 computer
Finally using a mix of Bib-1 and GILS attributes could look
something like this:
f @attrset Bib-1 @and @attr GILS 1=2008 Washington @attr 1=21 weather
For the full specification of the Prefix Query see the section
Prefix Query Format.