Valentine Cards - These items refer to 'cards' and 'photos' received from Gaia NPC or fellow Gaians who send valentine themed PMs. These items can not be equipped and are strictly image based and can be accessed via the user's inventory. These date back to 2009.
Valentine series - This could refer to any time with a themed based on Valentine's Day. This includes things like hearts, flowers, chocolates, roses, plushes, and colors such as red, pink, and white. These date back to 2008.
Faction items - Similar to corporation items in that it means siding with a character group to obtain their items. Thus far the only faction items relating to Valentine's Day have been Pro and Anti. These date back to 2011.
Shop items - Stocked in shops, these are items released for the sake of the season or for the theme of the event. Unlike event items they cost gold, stickers, or cash.