By default, the CellToolTip property is "..." (three dots). If the CellToolTip property is "..." the control displays the cell's caption if it doesn't fit the cell's client area. If the CellToolTip property is different than "...", the control shows a tooltip that displays the CellToolTip value.  The control  fires the ToolTip event when the column's tooltip is about to be displayed. Use the ToolTipWidth property to specify the width of the tooltip window. The ToolTipPopDelay property specifies the period in ms of time the ToolTip remains visible if the mouse pointer is stationary within a control. The ToolTipDelay property specifies the time in ms that passes before the ToolTip appears. Use the <font> element to specify a different font or size for the tooltip, or use the ToolTipFont property to specify a different font or size for all tooltips in the control. Use the ItemBar(,,exBarToolTip) property to specify a tooltip for a bar. Use the Link(,exLinkToolTip) property to specify the tooltip to be shown when the cursor hovers the link.

The tooltip supports the following HTML tags:

• <b>  bold </b> bolds a part of the caption.
• <u> underline </u> specifies that the portion should appear as underlined. 
• <s> strikeout </s> specifies that the portion should appear as strikeout. 
• <i> italic </i> specifies that the portion should appear as italic. 
• <fgcolor=FF0000> fgcolor </fgcolor> changes the foreground color for a portion.
• <bgcolor=FF0000> bgcolor </bgcolor> changes the background color for a portion.
• <br> breaks a line.
• <solidline> draws a solid line. If has no effect for a single line caption.
• <dotline> draws a dotted line. If has no effect for a single line caption.
• <upline> draws the line to the top of the text line
• <r> aligns the rest of the text line to the right side. It has no effect if the caption contains a single line.
• <img>number[:width]</img> inserts an icon inside the cell's caption. The number indicates the index of the icon being inserted. Use the Images method to assign a list of icons to your chart. The last 7 bits in the high significant byte of the number expression indicates the identifier of the skin being used to paint the object. Use the Add method to add new skins to the control. If you need to remove the skin appearance from a part of the control you need to reset the last 7 bits in the high significant byte of the color being applied to the part. The width is optional and indicates the width of the icon being inserted. Using the width option you can overwrite multiple icons getting a nice effect. By default, if the width field is missing, the width is 18 pixels.
• <img>key[:width]</img> inserts a custom size picture being loaded using the HTMLPicture property. The Key parameter indicates the key of the picture being displayed. The Width parameter indicates a custom size, if you require to stretch the picture, else the original size of the picture is used.
• <font face;size>text </font> displays portions of text with a different font and/or different size. For instance, the <font Tahoma;12>bit</font> draws the bit text using the Tahoma font, on size 12 pt. If the name of the font is missing, and instead size is present, the current font is used with a different size. For instance, <font ;12>bit</font> displays the bit text using the current font, but with a different size.
• & glyph characters as &amp ( & ), &lt ( < ), &gt ( > ), &qout ( " ), &#number, For instance, the &#8364 displays the EUR character, in UNICODE configuration. The & ampersand is only recognized as markup when it is followed by a known letter or a # character and a digit. For instance if you want to display <b>bold</b> in HTML caption you can use &lt;b&gt;bold&lt;/b&gt;

Also, newer HTML format supports decorative text like follows:

• <gra rrggbb;mode;blend> ... </gra> defines a gradient text. The text color or <fgcolor> defines the starting gradient color, while the rr/gg/bb represents the red/green/blue values of the ending color, 808080 if missing as gray. The mode is a value between 0 and 4, 1 if missing, and blend could be 0 or 1, 0 if missing. The <font> HTML tag can be used to define the height of the font. Any of the rrggbb, mode or blend field may not be specified. The <gra> with no fields, shows a vertical gradient color from the current text color to gray (808080). For instance the "<font ;18><gra FFFFFF;1;1>gradient-center</gra></font>" generates the following picture:

  

• <out rrggbb;width> ... </out> shows the text with outlined characters, where rr/gg/bb represents the red/green/blue values of the outline color, 808080 if missing as gray, width indicates the size of the outline, 1 if missing. The text color or <fgcolor> defines the color to show the inside text. The <font> HTML tag can be used to define the height of the font. For instance the "<font ;31><out 000000><fgcolor=FFFFFF>outlined</fgcolor></out></font>" generates the following picture:

  

• <sha rrggbb;width;offset> ... </sha> define a text with a shadow, where rr/gg/bb represents the red/green/blue values of the shadow color, 808080 if missing as gray, width indicates the size of shadow, 4 if missing, and offset indicates the offset from the origin to display the text's shadow, 2 if missing. The text color or <fgcolor> defines the color to show the inside text. The <font> HTML tag can be used to define the height of the font.  For instance the "<font ;31><sha>shadow</sha></font>" generates the following picture:

  

  or  "<font ;31><sha 404040;5;0><fgcolor=FFFFFF>outline anti-aliasing</fgcolor></sha></font>" gets:

  

Note: The intersection of an item with a column defines a cell. Each cell is uniquely represented by its handle. The cell's handle is of HCELL type, that's equivalent with a long type. All properties of Items object that have two parameters Item and ColIndex, that refers a cell.