This document provides guidelines on submission of Supplementary Information (SI), including content of SI, the type of files we can accept, the size constraints for individual files and how SI should be presented.
Supplementary Information (SI) is peer-reviewed material directly relevant to the conclusion of a paper that cannot be included in the printed version for reasons of space or medium (for example, movie clips or sound files). SI is not subedited so authors should ensure that it is clearly and succinctly presented, and that the style of terms conforms with the rest of the paper. During SI processing for online publication, standard house formatting will be applied but the contents will remain unchanged.
SI is posted on the freely available part of our website at the time of publication and cannot be hosted solely on the authors' own websites for peer-review or publication purposes. Nor can the author alter it after the paper has been accepted for publication. We do not take responsibility for the maintenance of any links or e-mail addresses provided in SI.
We recommend that SI in the following five 'flat' (text or table) categories is combined into a single PDF, laid out as you wish readers, editors and peer-reviewers to download it.
- Supplementary Methods
- Supplementary Table(s)
- Supplementary Discussion
- Supplementary Equation(s)
- Supplementary Notes (including notes clarifying statistical analyses, acknowledgements, grant or other numbers)
Some types of SI (listed below) are either best presented in editable format or cannot be presented as PDF for technical reasons. Please supply these types of SI in one of our allowable formats. They will be published with the PDF of the rest of your SI, downloadable as separate files. Note that Tables may be included in Supplementary Information, but only if they are unsuitable for formatting as Extended Data tables (for example, tables containing large data sets or raw data that are best suited to Excel files).
- Supplementary Data
- Supplementary Video(s)
- Supplementary Audio(s)
- Supplementary Video and Audio Legend(s) (please provide legends in a separate editable document, or include in the SI Guide; see below)
Tips and hints for presentation of SI
SI sections should be classified as one of the categories listed above. Please note that we do not encourage deposition of references within SI as they will not be live links and will not contribute towards citation measures for the papers concerned. Authors who nevertheless wish to post reference lists should continue the numbering from the last reference listed in the print version, rather than repeating the numbering in the print version.
Supplementary tables must have a separate numbering system from that used for tables in the print version of the paper and the Extended Data (the first table displayed in SI should be labelled 'Supplementary Table 1' and so on).
With your SI, please include an additional 'SI Guide' text file named SIGuide.doc. This should contain:
- A title for each file. For example, for a merged PDF: Supplementary Methods; Supplementary Notes. For example, for SI supplied as separate files: Supplementary Table
- A text summary for each file (no more than 50 words) that describes the contents of the file. Descriptions of individual tables should be provided if these items are submitted as separate files. For SI submitted together in one PDF, the description should indicate how many display items and what type of text are contained within the file, and provide a general description of what the display items collectively show. These summaries will be displayed under the SI download link online as a guide for readers.
For Supplementary Video and Audio files, please provide a one-sentence title and a short legend (no more than 100 words and without reference citations) for each video/audio file. Please include this information in a separate editable file (or include in the SIGuide document) and not in the main SI PDF. Ensure that discrete pieces of the SI (for example, videos) are referred to at least once in the print version of the paper at an appropriate point in the text.
Format and file sizes
Ensure that file sizes are as small as possible so that users can download them quickly. Images should be a maximum size of 640 x 480 pixels (9 x 6.8 inches at 72 pixels per inch). We prefer to accept no more than ten files. Sound/video files and combined, single PDFs may be up to 30 MB per file, with the maximum cumulative size of all files not exceeding 150 MB. Please note that these limits are absolute maxima that we cannot exceed under any circumstances, and it is expected that most SI PDFs will be considerably smaller than this.
We accept files in any of the following formats:
- Adobe Acrobat (.pdf) (preferred)
- MS Word document (.doc, .docx)
- Plain ASCII text (.txt)
- Rich Text Format (.rtf)
- WordPerfect document (.wpd)
- PostScript (.ps)
- Encapsulated postcript (.eps)
- HTML document (.htm)
- MS Excel spreadsheet (.xls, .xlsx)
- QuickTime movie (.mov) (preferred)
- Audio file (.wav)
- MPEG/MPG animation (.mpg, .mp4, .mp3)
- Systems Biology Markup Language (.sbml, .xml, .owl)
For optimal-quality videos please use a H.264 encoding, the standard aspect ratio of 16:9 (4:3 is second best) and do not compress the video.
If your file sizes exceed these limits or if you cannot submit in these formats, please seek advice from the editor handling your manuscript. Should you require assistance with file formats or uploading of your SI, please contact us at firstname.lastname@example.org.
Submitting Supplementary Information
For initial submissions, SI can be submitted online with the rest of the paper via our online submission service. When a paper with SI is accepted, SI in its final form should be uploaded to our server via our online submission service. In addition to the SI files, please also upload the SIGuide.doc as specified above.
Supplementary Information checklist
Please check the following when submitting SI:
- Each piece of SI designated to one of nine categories with a separate numbering system from that used for display items in the print version of the paper and the Extended Data.
- Formats are among those accepted by Nature.
- Individual and cumulative file sizes are within permitted limits.
- SIGuide.doc text file submitted containing titles of each SI file, descriptive summaries, and video/audio titles and legends.
Microarrays and other databases
Please see the MGED open letter specifying microarray standards. Authors submitting manuscripts containing microarray data must submit the data to the GEO or ArrayExpress databases, with accession numbers at or before acceptance for publication. The data must be MIAME-compliant, with all variables completed. See Nature editorial of 26 September 2002 for further details and explanation.