The GEN:AlternatingItemTemplate tag creates an alternating layout in a table. The contents of the AlternatingItemTemplate tag are used for each of the alternating records retrieved from the database table.
The AlternatingItemTemplate tag may contain a layout that is different than the ItemTemplate tag. For example, not only can the background color of the alternating row be different, but you can also show a completely different set of fields on the two rows. If the same fields are being used in the two templates, then the names of the tags can be the same. The restriction of unique names within a page does not apply to the tags across the ItemTemplate and AlternatingItemTemplate tags.