"Keywords" are special words which represent an ability, some of them are identified by having an own symbol. They work as a form of shorthand in order to save both space on the card text and time when reading them. Keywords are also one of the things that can be referenced by card effects, e.g. a card can give/remove a keyword to/from a card or give a bonus to a card that has a specific keyword.
In card texts, a reminder text about the keyword may be included, which is shown as parenthesized italicized text which explains the main function of the ability. The reminder text itself has no effect on gameplay, but reminds the players of the rules about how the keyword ability works.
With the release of G Clan Booster 1: Academy of Divas, all clans have a keyword exclusive to their own cards, which either works as a specific action, requirement, restriction, or a unit's state.
Despite Link Joker being the first clan to have a keyword exclusive to it (Delete) and the only clan to have both the Delete and Vanish Delete keywords, neither are recognized as the clan's official keyword during the Cardfight!! Vanguard G era; thus, Link Joker is currently the only clan to not have any official exclusive keywords.
Some clan exclusive keywords have a grade 3 unit that possesses the ability to search for a card with the keyword ability from the top five cards from the deck upon riding by paying a certain cost (usually [Counter Blast (1) & Soul Blast (1)]).
List of Keywords