method FormatAppearances.Add (Key as String, [Name as Variant])
Adds a FormatAppearance object and returns a reference to the newly created object.

Key as String A String expression that specifies the unique key of the FormatAppearance object. The Key of the FormatAppearance should include only alpha-numeric characters, any other character will be ignored.
Name as Variant A String expression that indicates the HTML caption to be displayed on the control's context menu.
FormatAppearanceA FormatAppearance object being created.

By default, the FormatAppearances collection contains the following keys: "bold", "italic", "underline" and "strikeout". Use the Clear method to remove all FormatAppearance objects from the FormatAppearances collection. Use the Remove method to remove a FormatAppearance object giving its key. Use the Item property to access a FormatAppearance object giving its key. The Key property indicates the key of the FormatAppearance object. 

The FormatAppearance object changes the visual appearance of your data as listed:

Use the Key of the FormatAppearance in [] to apply the specified object to any column or row. For instance, the PivotRows property on "0[bold,italic]" to group by the first column and shows the column's content in bold and italic. The same rule is applied to PivotColumns or PivotTotals property.