Add {{References missing|detail}} to the top of the description page of the file, replacing "detail" with what exactly is missing. To specify the talk page section for discussion, use {{References missing|detail|talksection=talk page section name}}.
If the description of the file seems to be wrong or not to match the content of the file please use {{Fact disputed}}.
{{References missing}} – generally for files where the description or depiction needs references
{{Datasource missing}} – for own diagrams and maps visualizing data that needs references
{{No source since}} – deletion warning for missing essential source information
{{Sourcefield}} - produces a warning that a file appears to have an invalid entry in its "Source" parameter; for use on user talk pages, not file pages; less serious than the {{No source since}} warning; does not threaten deletion