The summary line format used in GroupLens-enhanced summary buffers. It accepts the same specs as the normal summary line format (see Summary Buffer Lines). The default is `%U%R%z%l%I%(%[%4L: %-20,20n%]%) %s\n'.

Host running the bbbd server. `grouplens.cs.umn.edu' is the default.

Port of the host running the bbbd server. The default is 9000.

Offset the prediction by this value. In other words, subtract the prediction value by this number to arrive at the effective score. The default is 0.

This variable allows the user to magnify the effect of GroupLens scores. The scale factor is applied after the offset. The default is 1.