Thanks to the list's help, I have my multiple output files. The next problem is that the displayed descriptions all have the identical text as the "master" (first output) file. I need to know which is which. The data in each file that my tool is indistinguishable, so I can't label the data internally. I need to precisely track which resultant dataset corresponds to which of the program's output streams. I can't even dead-reckon, because the datasets appear to be randomly ordered with respect to either the file's creation time or its original name. It would be _really_ nice if the output name extracted from the file name could be included in (or just be) the dataset name displayed in the history. That would give the program control of the displayed name, which would be extremely helpful. I see a tantalizing clue at the bottom of the ToolsMultipleOutput page, to reference "__collected_datasets__['primary'][name]." in a post processing hook. However, I can't find any reference to post processing hooks in the wiki or on Google. I'd welcome a pointer to any documentation about post-processing. Is there a documentation section that I'm overlooking? Thanks for the support, -Al