The font size in the table does not respect the CSS for the corresponding class. There is similar issue with <li /> element. 

If the value from the source contains new lines, they should be inserted in the resulting documents as new paragraphs.

Workaround:
Copy the default styles after the Mail Merge

RadFlowDocument merged = sourceDocument.MailMerge(mailMergeSource);
merged.DefaultStyle.ParagraphProperties.CopyPropertiesFrom(sourceDocument.DefaultStyle.ParagraphProperties);
merged.DefaultStyle.CharacterProperties.CopyPropertiesFrom(sourceDocument.DefaultStyle.CharacterProperties);

The AltChunk element is responsible for embedding external content into documents.

According to the OOXML specification the shading color can be defined only in RRGGBB hex color, but MS Word also supports colors defined with their names - e.g. "Red".

Table and table cell borders are not evaluated according to inheritance and conflict resolution rules. A conflict will occur when different borders from the table and table cell are overlapping. 

The GetActualValue method of the TableBorders and TableCellBorders could potentially return an incorrect value in some of the following scenarios:

Scenario 1:
A table has cell spacing set to 0. Meaning that the table and table cell borders will overlap.
The table borders have defined all of its borders with border style "Single".
The table cell borders have all of its borders defined with border style "None".

Expected result: the resulting borders should have the border style set to "None" for the location where the table and the cell borders are overlapping.

Scenario 2:
A table has explicitly defined that its right border is with border style "None".
The table has a table style applied with defined border style of type "Single" for all table borders.

Expected result: All of the table borders except the right border should have border style of "Single".

The problem is mostly visible when exporting to PDF and RTF format.

When table row is empty, it's exported to PDF with incorrect height - depending on the type of height set with 0 or with the height of an empty paragraph.

When a paragraph has defined tab stops in its style and has the same tab stops locally cleared, the tab stops are still respected when exporting to PDF. Instead, cleared tab stops should not be respected.

Currently Run.Shading is not exported to PDF.

Note: This scenario is common when converting HTML to PDF, as Run.Shading is set when construct like <span style="background-color:#ffcc00;"> is used.

Workaround: Iterate all the Runs in the already imported HTML document and set their HighlightColor to Shading.BackgroundColor.LocalValue. Check this code snippet:

foreach (Run run in document.EnumerateChildrenOfType<Run>())
{
	if (!run.Properties.HighlightColor.HasLocalValue)
	{
		run.HighlightColor = run.Shading.BackgroundColor.LocalValue;
	}
}

In MS Word you can crop the image from Picture Tools -> Format -> Size -> Crop button in the ribbon. This preserves the whole image in the file, but when it is rendered it shows only the cropped image area.

This is described with 'srcRect' element in OOXML.

Workaround:

private static void WorkaroundFieldsIssue(RadFlowDocument flowdocument)
{
    foreach (FieldCharacter fieldCharacter in flowdocument.EnumerateChildrenOfType<FieldCharacter>().ToList())
    {
        // only for start
        if (fieldCharacter.FieldCharacterType == FieldCharacterType.Start)
        {
            if (fieldCharacter.FieldInfo.Separator != null && fieldCharacter.FieldInfo.Separator.Parent == null)
            {
                Paragraph parent = fieldCharacter.FieldInfo.End.Paragraph;
                int index = parent.Inlines.IndexOf(fieldCharacter.FieldInfo.End);

                fieldCharacter.FieldInfo.End.Paragraph.Inlines.Insert(index, fieldCharacter.FieldInfo.Separator);
            }
        }
    }
}

The tblGrid property should be exported in order to visualize properly the documents in some viewers. For example, LibreOffice doesn't visualize properly tables  without specified width.

Take into account the table row's CanSplit property when exporting to PDF from RadFlowDocument model. Is set to false, the table row should not be split between two pages, if possible.

This property could be set to false, for example, when importing MS Word documents with "Allow row to break across pages" unchecked for some table rows.

Implement repeating header row for tables when exporting with PdfFormatProvider.

A similar functionality can be achieved using the editing API of RadPdfProcessing. There is attached a project showing a sample implementation. More details are available in the forum post at http://www.telerik.com/forums/repeat-table-heading-after-page-break#kH616fyAKUiDl6WAknUILg

Add support for INCLUDEPICTURE fields. Such fields should work with nested MERGEFIELD, as this is common scenario.

Workaround: Manually insert images over specific placeholder
RadFlowDocument document = new RadFlowDocument();
RadFlowDocumentEditor editor = new RadFlowDocumentEditor(document);
  
editor.InsertText("1");
editor.InsertText("EXAMPLE_IMAGE");
editor.InsertText("2");
  
foreach (var run in editor.Document.EnumerateChildrenOfType<Run>().ToArray())
{
    if(run.Text == "EXAMPLE_IMAGE")
    {
        Paragraph paragraph = run.Paragraph;
        int indexOfCurrentRun = paragraph.Inlines.IndexOf(run);
        paragraph.Inlines.RemoveAt(indexOfCurrentRun);
  
        ImageInline imageInline = new ImageInline(document);
        imageInline.Image.ImageSource = newTelerik.Windows.Documents.Media.ImageSource(imageData, "png");
        paragraph.Inlines.Insert(indexOfCurrentRun, imageInline);
    }
}

The vertical alignment of the table cells is not exported to PDF. The values are always exported with top alignment.

When table cell preferred width is smaller than the first word in the cell the actual exported width should fit the word width when exporting to PDF. 

Currently in such case the word is split into two lines. The width has to be equal to the word width so the word stays on a single row.

The property controls whether a paragraph should be rendered at least partially on the same page with the following paragraph when the document is shown in page view mode.