[galaxy-dev] <repeat> tag

Hi, I was wondering if I could get some more information on how the <repeat> tag works. If I am repeating an argument, say "$samplename," would the xml file just pass extra arguments to my command line, or do I have to do some extra configuration? If it is passing extra arguments, are they lumped together? For example if I want to repeat both $samplename and $lane using the same tag, is it sending to the command line $samplename1 $samplename2 $samplename3 $lane1 $lane2 $lane3 or $samplename1 $lane1 $samplename2 $lane2 $samplename3 $lane3? What types are supported by the <repeat> tag? Currently I am using type="text" but this does not seem to be working. Thanks!