/**
	 * Return the comment rich edit text of the left top cell of this Range.
	 * @return the rich edit text of this Range.
	 * @since 3.6.1
	 */
	public String getCommentRichText();

	/**
	 * Set comment rich text into the left top cell of this range; null to 
	 * delete it. 
	 * @since 3.6.1
	 */
	public void setCommentRichText(String html);

	/**
	 * Set comment visibility into the left top cell of this range; if no
	 * comment at the cell, it simply ignored.
	 * @param visible
	 * @since 3.6.1
	 */
	public void setCommentVisible(boolean visible);
	
	/**
	 * Returns whether the comment is always visible at the left top cell of
	 * this range; if no comment at the cell, it returns false.
	 * @return
	 * @since 3.6.1
	 */
	public boolean isCommentVisible();