Parameter and Command Reference > Connector Framework Server Parameters > Import Tasks and their Parameters > PreN 

PreN 
PreN is used to specify tasks when documents are indexed into IDOL server. Pre tasks are called before file content is filtered out and before sub-files are extracted. Tasks must be numbered starting from zero (0).
The import tasks that can be called by PreN are IdxWriter, Lua, HtmlExtraction, and TextToDocs.
The fields AUTN_NO_FILTER and AUTN_NO_EXTRACT can be used to customise the task.
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To prevent sub files being extracted from the document, set the value of AUTN_NO_EXTRACT to true This setting might be used to prevent the contents of zip files being indexed.
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To prevent any content being filtered out of the document, set the value of AUTN_NO_FILTER to true This setting might be used to prevent content being indexed from a certain file type.
 
Pre0=Lua:C:\Scripts\pretask1.lua