The default Sitefinity implementation does not allow the upload of .svg files in the Images module. However you are able to do so if you choose to upload them in the Documents module. The file will not be threated as an image, but as a document, meaning it will not display, but rather start a download once clicked. The svg file will either download or display in a new tab depending on the browser's default behavior.
Sitefinity's documents do not have mime types and do not require you to register such neither in the backend, nor in your IIS. Mime types are important if you deal with Images and Videos, but not in the current case.
If you want to display the images, I can advise you store them in a content block that can be saved as shared content. The way to proceed with this is to include the xml directly on the page/template or using a content block and place the markup in the HTML window. Please view this video
for further reference.
Ivan D. Dimitrov
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