When the user enter text using the keyboard the PositionChanged event of the CaretPosition is not fired.
The item's status changed to Declined - the LocationChanged event can be used to track when the location of the position has been changed.

In Material theme, RadRichTextBox should be enclosed by border.
In Fluent theme, RadRichTextBox should have shadow.

The problems are more visible when RadRichTextBox.LayoutMode is Flow, but the border/shadow should also be present in Paged layout mode.

Fix available in R3 2018 SP1 release.

Seems that the algorithm is not showing the appropriate results when a word has apostrophe. For example typing "etre" does not suggest "être".

A custom third-party spell checker library - NHunspell can be used. 
SDK Example demonstrating this approach can be found in our XAML-SDK portal:
https://github.com/telerik/xaml-sdk/tree/master/RichTextBox/NHunspellSpellChecking

Import description lists: <dl>, <dt>, <dd> tags.

Possible way for implementation is with paragraphs with left margin.

Whenever the focus is on RadRichTextBox, the keyboard is displayed with Uppercase by Default. After inputting 2-3 characters in uppercase, it changes to lowercase and then alternates between uppercase and lower per character.

When a data provider is used, the designer does not show the RadRichTextBox content, that is shown with no problem at run time.

Workaround: The issue is with finding the format provider used by the data provider. This issue appears at design time only. The workaround is to manually set the format provider of the data provider:
        <telerik:HtmlDataProvider
            x:Name="htmlDataProvider"
            RichTextBox="{Binding ElementName=radRichTextBox, Mode=OneWay}"
            Html="&lt;h1&gt;Header3&lt;/h1&gt;">
            <telerik:HtmlDataProvider.FormatProvider>
                <telerik:HtmlFormatProvider />
            </telerik:HtmlDataProvider.FormatProvider>
        </telerik:HtmlDataProvider>

When spell checking dialog is used for spell checking, and the user proceeds to the next word (either by changing with a suggestion, ignoring, etc.), the view port is not scrolled to include the next currently spell checked word.

Fix available in R3 2018 Official Release.

When the first table cell for a table row is vertically merged, the height of the row is exported improperly - instead the height of the row containing the beginning of the merged cell is exported.

Open a docx file in richtextbox, if numpages in headers do any subtraction, it can not display correctly. see the attached pictures for how to display in richtextbox and microsoft word 2016.

When RTF documents are imported simultaneously in different threads, sometimes ArgumentException with message "An item with the same key has already been added" is thrown with the following call stack:

at System.Collections.Generic.Dictionary`2.Insert(TKey key, TValue value, Boolean add)
   at System.Collections.Generic.Dictionary`2.Add(TKey key, TValue value)
   at Telerik.Windows.Documents.FormatProviders.ReplaceStyleNameHandler.Add(String displayName, String name)
   at Telerik.Windows.Documents.FormatProviders.ReplaceStyleNameHandler.InitializeStyleDisplayNameToStyleNameDictionary()
   at Telerik.Windows.Documents.FormatProviders.ReplaceStyleNameHandler.get_StyleDisplayNameToStyleName()
   at Telerik.Windows.Documents.FormatProviders.ReplaceStyleNameHandler.TryGetStyleNamesByStyleName(String displayName, RadDocumentDefaultStyleInfo& defaultStyleInfo)
   at Telerik.Windows.Documents.FormatProviders.ReplaceStyleNameHandler.Replace(ReplaceStyleNameContext context)
   at Telerik.Windows.Documents.FormatProviders.Rtf.Import.RtfStyleImporter.DoVisitText(RtfText text)
   at Telerik.Windows.Documents.FormatProviders.Rtf.Import.RtfElementIteratorBase.VisitElement(RtfElement element, Boolean recursive)
   at Telerik.Windows.Documents.FormatProviders.Rtf.Import.RtfElementIteratorBase.VisitGroupChildren(RtfGroup group, Boolean recursive)
   at Telerik.Windows.Documents.FormatProviders.Rtf.Import.RtfStyleImporter.ImportStyleGroup(RtfGroup group)
   at Telerik.Windows.Documents.FormatProviders.Rtf.Import.RtfStylesTable.FillStyle(RtfGroup group, StyleType type, Boolean isDefault)
   at Telerik.Windows.Documents.FormatProviders.Rtf.Import.RtfStylesTable.DoVisitGroup(RtfGroup group)
   at Telerik.Windows.Documents.FormatProviders.Rtf.Import.RtfElementIteratorBase.VisitElement(RtfElement element, Boolean recursive)
   at Telerik.Windows.Documents.FormatProviders.Rtf.Import.RtfElementIteratorBase.VisitGroupChildren(RtfGroup group, Boolean recursive)
   at Telerik.Windows.Documents.FormatProviders.Rtf.Import.RtfStylesTable.ReadTable(RtfGroup group, RtfImportContext context)
   at Telerik.Windows.Documents.FormatProviders.Rtf.Import.RtfHandlers.RtfGroupHandlers.StylesTableHandler(RtfGroup group, RtfImportContext context)
   at Telerik.Windows.Documents.FormatProviders.Rtf.Import.RtfDocumentImporter.DoVisitGroup(RtfGroup group)
   at Telerik.Windows.Documents.FormatProviders.Rtf.Import.RtfElementIteratorBase.VisitElement(RtfElement element, Boolean recursive)
   at Telerik.Windows.Documents.FormatProviders.Rtf.Import.RtfElementIteratorBase.VisitGroupChildren(RtfGroup group, Boolean recursive)
   at Telerik.Windows.Documents.FormatProviders.Rtf.Import.RtfDocumentImporter.ImportRoot(RtfGroup rtfGroup)
   at Telerik.Windows.Documents.FormatProviders.Rtf.Import.RtfDocumentImporter.Import(Stream input, RtfImportSettings settings)
   at Telerik.Windows.Documents.FormatProviders.Rtf.RtfFormatProvider.Import(Stream input)
   at Telerik.Windows.Documents.FormatProviders.Rtf.RtfFormatProvider.Import(String input)

Fix available in LIB Version 2018.3.924.

When the rtf document contains a table as the one below and the empty declaration is used in the following structure, the document cannot be imported:

{\fonttbl
{\f0 Verdana;}
{\f1 Times New Roman;}
{\f2 ;}
{\f3 Segoe UI;}}

Having a table with specified RowSpan and further exported to PDF does not draw the border. This is due to export optimization caused by the fact whether there is or is not a CellSpacing specified.

Workaround: Set really small CellSpacing for the table.

API ideas:

- DocumentSelection: Get inlines between annotation start and end, e.g. DocumentSelection.EnumerateChildrenOfType<>(bool includePartiallySelectedElements) where T : DocumentElement

- DocumentSelection: SelectAnnotationRange(AnnotationRangeStart start, bool includeAnnotation). Such method is present without the last parameter, but it always selects the annotation ranges

When pressing Shift+Up(Down) should create a selection to the start(end) of the document when the caret position is on the first(last) line. Currently, in this case, a selection is not created.

Such behavior can be achieved using the following approach:

        private void RadRichTextBox_CommandExecuting(object sender, CommandExecutingEventArgs e)
        {
            if (e.Command is MoveCaretCommand && System.Windows.Input.Keyboard.Modifiers == ModifierKeys.Shift)
            {
                var command = e.Command as MoveCaretCommand;
                MoveCaretDirections direction = (MoveCaretDirections)e.CommandParameter;
                if (direction == MoveCaretDirections.Up)
                {
                    var positionOnFirstLine = new DocumentPosition(this.radRichTextBox.Document);
                    positionOnFirstLine.MoveToFirstPositionInDocument();
                    if (this.radRichTextBox.Document.CaretPosition.Location.Y - positionOnFirstLine.Location.Y < 1)
                    {
                        this.radRichTextBox.Document.CaretPosition.MoveToPosition(positionOnFirstLine);
                        e.Cancel = true;
                    }
                }
                else if (direction == MoveCaretDirections.Down)
                {
                    var positionOnLastLine = new DocumentPosition(this.radRichTextBox.Document);
                    positionOnLastLine.MoveToLastPositionInDocument();
                    if (positionOnLastLine.Location.Y - this.radRichTextBox.Document.CaretPosition.Location.Y < 1)
                    {
                        this.radRichTextBox.Document.CaretPosition.MoveToPosition(positionOnLastLine);
                        e.Cancel = true;
                    }
                }
            }
        }

The exception is reproduced only with specific custom fonts and is thrown by the ComputeSubset() method of the GlyphTypeface class with the following message: "file does not conform to the expected file format specification". However, we can handle the exception and export the font data using the base class.

Available in LIB Version 2018.2.820.

After performance investigation related to feedback item http://feedback.telerik.com/Project/143/Feedback/Details/171108 , one bottleneck was identified as redundant calls to internal methods for getting parent of a document element.

Available in LIB Version 2018.2.820.

At this point, the FloatingUIContainers cannot be selected. Implement selection to enable the users to work easily with such elements.

In Office Open XML documentation there is element named "AlternateContent" which can contain image. Currently the content inside the AlternateContent element is skipped. 

The pgMar element might be present but the margin information might be missing as shown below:
<w:pgMar w:header="720" w:footer="720" />
At the moment this overwrites the section margin information with 0. Instead the margins should remain as is.

Fix available in LIB Version 2018.2.820.

Certain documents containing a table with a cell spanning on more than one row might cause the application to hang and throw OutOfMemoryException.

Workaround: Set SpacingAfter = 0 of the last paragraph in the table.