When the table is nested in another table with fixed-width and the nested one has more than one cell in the row, where the one has a preferred width set to auto and the other has content that split on more than one row, then the first cell is exported with a wrong width.

You can add captions to figures, equations, or other objects.

From the Office Open XML File Formats Specification: This element specifies the contents and positioning for captions which can be used to automatically label objects in a WordprocessingML document. A caption is a string that labels an object included in a WordprocessingML document, and typically consists of a string plus a field which numbers this item within a collection of similar objects.

Similar functionality can be achieved using the CustomCodeField:

RadFlowDocumentEditor editor = new RadFlowDocumentEditor(document);
using (Stream stream = File.OpenRead("Image1.jpg"))
{
	ImageInline image = editor.InsertImageInline(stream, "jpg");
	editor.InsertBookmark("Image", image, image);
}

editor.InsertBreak(BreakType.LineBreak);
editor.InsertText("Figure ");
editor.InsertField("SEQ Image", "Update Figure Number");

Background properties do not inherit, but the parent element's background will shine through by default because of the initial 'transparent' value on 'background-color'.

HTML content:

<div style="background-color: gray; color: red">
Text outside the list
	<ul>
		<li>
			Text in the list
		</li>
	</ul>
</div>

The result when exported to DOCX/PDF:

Workaround: set the style directly to the <ul> element:

<div style="background-color: gray; color: red">
Text outside the list
	<ul style="background-color: gray;">
		<li>
			Text in the list
		</li>
	</ul>
</div>

When we have Document properties set (no Section properties set) and the \sectd control word is missing the Document properties are not respected.

From the RTF Specification: When we have Section properties set the \sectd resets the values to that specified by the Document properties. But when we don't have Section properties set and the \sectd is missing we should inherit the values specified by the Document properties

When exporting a document containing a Field that has no Separator set the content after this field is omitted.

According to the OOXML Specification, the fldCharType value separate is optional. 

 Exception trying to import HTML that contains width with an empty value. For example:

<table width="">

When replacing a string within a run that is not the first element in the paragraph an unexpected behavior occurs.

These are the known cases:

• System.ArgumentOutOfRangeException: 'Index and length must refer to a location within the string. Parameter name: length'
• System.InvalidCastException: 'Unable to cast object of type <<type>> to type 'Telerik.Windows.Documents.Flow.Model.Run'.'
• Shifted text.