refresh_pattern [-i] regex min percent max [options]

[chudy fernandez <chudy_fernandez@xxxxxxxxx>]

i have
refresh_pattern -i (get_video\?|videoplayback\?|videodownload\?)    161280     50000%     525948    override-expire override-lastmod

I don't know it's acceptable. what are the limits(maximum) for min, percent and max?