The Fossil /doc page uses filename suffixes and the following tables to guess at the appropriate mimetype for each document. Mimetypes may be customized and overridden using the mimetypes config setting.
Default built-in mimetypes
| Suffix | Mimetype | 
|---|---|
| ai | application/postscript | 
| aif | audio/x-aiff | 
| aifc | audio/x-aiff | 
| aiff | audio/x-aiff | 
| arj | application/x-arj-compressed | 
| asc | text/plain | 
| asf | video/x-ms-asf | 
| asx | video/x-ms-asx | 
| au | audio/ulaw | 
| avi | video/x-msvideo | 
| bat | application/x-msdos-program | 
| bcpio | application/x-bcpio | 
| bin | application/octet-stream | 
| bmp | image/bmp | 
| bz2 | application/x-bzip2 | 
| bzip | application/x-bzip | 
| c | text/plain | 
| cc | text/plain | 
| ccad | application/clariscad | 
| cdf | application/x-netcdf | 
| class | application/octet-stream | 
| cod | application/vnd.rim.cod | 
| com | application/x-msdos-program | 
| cpio | application/x-cpio | 
| cpt | application/mac-compactpro | 
| cs | text/plain | 
| csh | application/x-csh | 
| css | text/css | 
| csv | text/csv | 
| dcr | application/x-director | 
| deb | application/x-debian-package | 
| dib | image/bmp | 
| dir | application/x-director | 
| dl | video/dl | 
| dms | application/octet-stream | 
| doc | application/msword | 
| docx | application/vnd.openxmlformats-officedocument.wordprocessingml.document | 
| dot | application/msword | 
| dotx | application/vnd.openxmlformats-officedocument.wordprocessingml.template | 
| drw | application/drafting | 
| dvi | application/x-dvi | 
| dwg | application/acad | 
| dxf | application/dxf | 
| dxr | application/x-director | 
| eps | application/postscript | 
| etx | text/x-setext | 
| exe | application/octet-stream | 
| ez | application/andrew-inset | 
| f | text/plain | 
| f90 | text/plain | 
| fli | video/fli | 
| flv | video/flv | 
| gif | image/gif | 
| gl | video/gl | 
| gtar | application/x-gtar | 
| gz | application/x-gzip | 
| h | text/plain | 
| hdf | application/x-hdf | 
| hh | text/plain | 
| hqx | application/mac-binhex40 | 
| htm | text/html | 
| html | text/html | 
| ice | x-conference/x-cooltalk | 
| ico | image/vnd.microsoft.icon | 
| ief | image/ief | 
| iges | model/iges | 
| igs | model/iges | 
| ips | application/x-ipscript | 
| ipx | application/x-ipix | 
| jad | text/vnd.sun.j2me.app-descriptor | 
| jar | application/java-archive | 
| jp2 | image/jp2 | 
| jpe | image/jpeg | 
| jpeg | image/jpeg | 
| jpg | image/jpeg | 
| js | text/javascript | 
| json | application/json | 
| kar | audio/midi | 
| latex | application/x-latex | 
| lha | application/octet-stream | 
| lsp | application/x-lisp | 
| lzh | application/octet-stream | 
| m | text/plain | 
| m3u | audio/x-mpegurl | 
| man | text/plain | 
| markdown | text/x-markdown | 
| md | text/x-markdown | 
| me | application/x-troff-me | 
| mesh | model/mesh | 
| mid | audio/midi | 
| midi | audio/midi | 
| mif | application/x-mif | 
| mime | www/mime | 
| mjs | text/javascript | 
| mkd | text/x-markdown | 
| mov | video/quicktime | 
| movie | video/x-sgi-movie | 
| mp2 | audio/mpeg | 
| mp3 | audio/mpeg | 
| mp4 | video/mp4 | 
| mpe | video/mpeg | 
| mpeg | video/mpeg | 
| mpg | video/mpeg | 
| mpga | audio/mpeg | 
| ms | application/x-troff-ms | 
| msh | model/mesh | 
| n | text/plain | 
| nc | application/x-netcdf | 
| oda | application/oda | 
| odp | application/vnd.oasis.opendocument.presentation | 
| ods | application/vnd.oasis.opendocument.spreadsheet | 
| odt | application/vnd.oasis.opendocument.text | 
| ogg | application/ogg | 
| ogm | application/ogg | 
| pbm | image/x-portable-bitmap | 
| pdb | chemical/x-pdb | 
| application/pdf | |
| pgm | image/x-portable-graymap | 
| pgn | application/x-chess-pgn | 
| pgp | application/pgp | 
| pikchr | text/x-pikchr | 
| pl | application/x-perl | 
| pm | application/x-perl | 
| png | image/png | 
| pnm | image/x-portable-anymap | 
| pot | application/mspowerpoint | 
| potx | application/vnd.openxmlformats-officedocument.presentationml.template | 
| ppm | image/x-portable-pixmap | 
| pps | application/mspowerpoint | 
| ppsx | application/vnd.openxmlformats-officedocument.presentationml.slideshow | 
| ppt | application/mspowerpoint | 
| pptx | application/vnd.openxmlformats-officedocument.presentationml.presentation | 
| ppz | application/mspowerpoint | 
| pre | application/x-freelance | 
| prt | application/pro_eng | 
| ps | application/postscript | 
| qt | video/quicktime | 
| ra | audio/x-realaudio | 
| ram | audio/x-pn-realaudio | 
| rar | application/x-rar-compressed | 
| ras | image/cmu-raster | 
| rgb | image/x-rgb | 
| rm | audio/x-pn-realaudio | 
| roff | application/x-troff | 
| rpm | audio/x-pn-realaudio-plugin | 
| rtf | text/rtf | 
| rtx | text/richtext | 
| scm | application/x-lotusscreencam | 
| set | application/set | 
| sgm | text/sgml | 
| sgml | text/sgml | 
| sh | application/x-sh | 
| shar | application/x-shar | 
| silo | model/mesh | 
| sit | application/x-stuffit | 
| skd | application/x-koan | 
| skm | application/x-koan | 
| skp | application/x-koan | 
| skt | application/x-koan | 
| smi | application/smil | 
| smil | application/smil | 
| snd | audio/basic | 
| sol | application/solids | 
| spl | application/x-futuresplash | 
| sql | application/sql | 
| src | application/x-wais-source | 
| step | application/STEP | 
| stl | application/SLA | 
| stp | application/STEP | 
| sv4cpio | application/x-sv4cpio | 
| sv4crc | application/x-sv4crc | 
| svg | image/svg+xml | 
| swf | application/x-shockwave-flash | 
| t | application/x-troff | 
| tar | application/x-tar | 
| tcl | application/x-tcl | 
| tex | application/x-tex | 
| texi | application/x-texinfo | 
| texinfo | application/x-texinfo | 
| tgz | application/x-tar-gz | 
| th1 | application/x-th1 | 
| tif | image/tiff | 
| tiff | image/tiff | 
| tr | application/x-troff | 
| tsi | audio/TSP-audio | 
| tsp | application/dsptype | 
| tsv | text/tab-separated-values | 
| txt | text/plain | 
| unv | application/i-deas | 
| ustar | application/x-ustar | 
| vb | text/plain | 
| vcd | application/x-cdlink | 
| vda | application/vda | 
| viv | video/vnd.vivo | 
| vivo | video/vnd.vivo | 
| vrml | model/vrml | 
| wasm | application/wasm | 
| wav | audio/x-wav | 
| wax | audio/x-ms-wax | 
| webp | image/webp | 
| wiki | text/x-fossil-wiki | 
| wma | audio/x-ms-wma | 
| wmv | video/x-ms-wmv | 
| wmx | video/x-ms-wmx | 
| wrl | model/vrml | 
| wvx | video/x-ms-wvx | 
| xbm | image/x-xbitmap | 
| xlc | application/vnd.ms-excel | 
| xll | application/vnd.ms-excel | 
| xlm | application/vnd.ms-excel | 
| xls | application/vnd.ms-excel | 
| xlsx | application/vnd.openxmlformats-officedocument.spreadsheetml.sheet | 
| xlw | application/vnd.ms-excel | 
| xml | text/xml | 
| xpm | image/x-xpixmap | 
| xsl | text/xml | 
| xslt | text/xml | 
| xwd | image/x-xwindowdump | 
| xyz | chemical/x-pdb | 
| zip | application/zip |