Thank you for writing.
It is not possible to specify RTF version when exporting the content in RadRichTextEditor
. However, you can always modify the exported file according to your requirement.
We already have an issue that the version of the RTF document is not saved when the content is exported. Here is the feedback item for your reference: https://feedback.telerik.com/Project/154/Feedback/Details/213505-fix-radrichtexteditor-the-version-of-the-rtf-document-is-not-saved-when-the-con
I hope this information helps. Should you have further questions I would be glad to help.
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