Forbidden Characters

Forbidden Characters are a new type of text featured on cards in the Duel Masters Trading Card Game.

Details
Forbidden characters are a type of encoding system that is first featured on a promo version of Forbidden. It encodes English and thus the forbidden Characters correspond to English characters. At first the text is considered having unknown meaning, but players had deciphered the text and it revealed the mysterious mechanic Seal. This mechanic is an unknown mechanic and thus many players thought it is a non-card object. Later on in the DMVSR season of the anime, a card named appeared and is used by Basara, and the seal mechanic was known to players. The card itself is actually a secret version of Dokindam X, The Legendary Forbidden which appears extremely rarely and is nearly impossible to obtain by regular players due to its extremely low packaging rate and thus high prices.

Despite forbidden characters are not Japanese characters, Forbidden character cards can be used in official tournaments. However, in order to prevent younger players from unable to recognize the card's effect, tournaments may disallow Forbidden character cards to be used. As a result, it is recommended to bring a proxy copy of the Japanese version of the card for reference purposes. Additionally, despite it references English text, cards with forbidden characters cannot be used in the English game, and is still a card in the Japanese game.

Examples of cards with Forbidden Characters
Red-End, Super Lightning Sonic was also seen played by Basara. Its name and race was in Japanese characters, but the ability and other card details were in forbidden characters.

Other Characters
Additionally, forbidden characters have been featured in creature's artworks, reading as follows:

Appearances in the anime
Only Basara is able of reading the forbidden characters, this being the reason why Zakira let him have the unsealed version of Forbidden. Later on, when Basara duels against Lucifer in a revenge match, the card of Red-End, Super Lightning Sonic had its effect changed from kanji to Forbidden Characters which only he could read, which influenced the outcome of the duel as Lucifer accidentally destroyed it and helped his opponent unseal the Dokindam X after playing a command.

Whenever a seal was removed, a number would be displayed in Forbidden Characters as ONE, TWO, THREE, FOUR, FIVE and SIX. Additionally, Forbidden Characters seem to appear around the creatures as well as on their cards.

The letters surrounding Red-End, spell out his name, REDEND

The letters showed during Dokindam's liberating and those shown on cards that seal the opponent's creatures read, SEAL

The letters on Redzone X's bracelets are (in no particular order), J-A-S-C-R-K-S