The custom report template requires the entry of a unique name. However, that name is not passed to the filename when the report is run. Therefore, when the custom report and the canned report (used as the basis of the template) are run at the same time, there is no indication which report is the custom one. The only visual differences are the alphanumeric string and the size of the file which would only be useful for someone familiar with the reports.
The custom report name defined when the report is built should be included on the name of the file.