When the paragraph starts with Annotation with SkipPositionBefore = true, TabForward command does not detect that the caret is actually at the beginning of paragraph, and inserts Tab character instead of changing left indent. Workaround: Subscribe to CommandExecuting and cancel the InsertTextCommand with parameter "\t" if the caret is at such position Steps to reproduce: - Insert a paragraph in the document. - Put the caret at the beginning of the paragraph and insert bookmark (without selection). - Put the caret at the beginning of the paragraph and press tab. Expected: Paragraph's Left indent is changed. Observed: Tab character is inserted.