The rarest are the genuine opening day guest pass decoders, equivalent of a backstage pass. They had an identity sticker and a braided neck cord attached and were made of heavy card stock. There were several hundred made, very rare and highly valued.
Forgeries: Be aware that many Los Angeles/Orange County area newspapers ran a full page insert with this design on it and distributed it in the advertising supplement (along with mfg. coupons) of the Sunday issue following the attraction's opening. The full sheet is worth more than one which has been cut out. The design was similar enough that forged passes were represented as genuine backstage passes. Printed on light cardstock. Several million were made, several million were thrown away with the newspaper.
The Annual Passholders Preview Event, which was a special ticketed event, distributed decoders to those who stood in line to question the builders. Several thousand 8 1/2 x 11" xerox copies of a decoder on white plain paper with the code printed around the edge were handed out to mostly collectors. Rare, but not highly valued.
The "Tan" decoder was only distributed in the first week. Many were used to wrap gum, clean fingernails or were similarly discarded in the queue area. Perhaps ten thousand (10,000) were made. Most rare. (bids ~$5 mint)
The "Green" decoder was distributed in the first month. A few boxes were misplaced and distributed to those who inquired a year later after all of the red ones had been distributed. Perhaps fifty thousand (50,000) were made. Moderately rare.
The "Red" decoder was widely distributed during the first year. Perhaps a million (1,000,000) were made. Common.