Officially embraced by the TRC and by Wizards of the Coast, the Revised Constructed format tries to eliminate "degenerate" deck strategies from the Contructed environment, such as the dreaded Psycho Tycho deck.
The only thing that distinguishes the Revised Contructed format from Unlimited Contructed is a list of six extra requirements for decks to be met; otherwise, there are no restrictions. These are:
Tycho Extension is banned (i. e., isn't allowed to be played).
Enterprise, Inc., Shields is banned.
Viral Pipeline is considered to have an additional keyword "Unique".
Scaldan is considered to have an additional keyword "Unique".
Precision Bribery is considered to have an additional sentence, "Trashing in this way cannot be prevented."
Code Viral Cache is considered to have an additional sentence, "Trashing in this way cannot be prevented."
The "UK Variant"
The UK variant has an additional seventh rule saying:
Bartmoss Memorial Icebreaker is considered to have an additional sentence, "Trashing in this way cannot be prevented."