"decree forbidding" is correct and usable in written English.
You can use it to refer to an official announcement that forbids certain activity or behavior. For example, "The mayor issued a decree forbidding residents from collecting firewood in the nearby forests."
Hitler's reply was a decree forbidding Germans to accept any Nobel Prize.
In 1624 the French Parlement passed a decree forbidding criticism of Aristotle on pain of death.
The subsequent debate among partners was muffled, partly by a decree forbidding them to talk to outsiders.
President Gomez refused to turn out competent officials and has issued a decree forbidding officers on active duty from taking part in politics.
The Rites Controversy raged on until 1704, when Pope Clement XI issued a decree forbidding Chinese Catholics to take part in such rites.
Now, in an unusual case of disciplinary action, the minister of defense, Sergei B. Ivanov, has dismissed a senior army commander, citing a new decree forbidding the practice.
A new presidential decree forbids Gazprom from reaching a settlement without getting the Kremlin's approval.
See U.S. proposed decree, Article II, § 4, and Article V. (d) The Government asks that the decree forbid standardization of trade practices through concerted agreement.
A rent-cap decree forbids any increase in rent for two years, and thereafter by only 5% in the third year.
Since the operative portion of the decree prohibits any financial connection between the attorney and the Union, the decree cannot stand; and to the extent any other part of the decree forbids this arrangement it too must fall.
For city governments, Article 4 in the 1900 decree forbids them from using the national flag with the coat of arms.
