The Import Variables command and the two Delete User Variables commands generate a report of actions taken while processing your documents. This report is displayed after processing the documents in the book. By default, this report is "view only," if you want to save this report for future reference, you must unlock it first with the F, l, k shortcut (that's Shift+F, then lowercase L, and lowercase K).
If you set the NoLog parameter to 1, the log file will not be displayed by default unless there were errors in the processing.
When importing a very large number of variables into many files, the creation of the log file can add to the processing time. If you want to completely disable the creation of the import log file, set the WriteImportLogFile parameter to 0 (zero). If this parameter is missing or set to any value other than 0, the import log file will be generated.