Context: Multiracial people who wanted to acknowledge their full heritage won a victory of sorts in 1997, when the Office of Management and Budget (OMB) changed the federal regulation of racial categories to permit multiple responses. This resulted in a change to the 2000 United States Census, which allowed participants to select more than one of the six available categories, which were, in brief: "White," "Black or African American," "Asian," "American Indian or Alaskan Native," "Native Hawaiian or other Pacific Islander," and "Other." Further details are given in the article: Race (U.S. census). The OMB made its directive mandatory for all government forms by 2003.

Question: What office is responsible for the census form changes?
Answer: the Office of Management and Budget (OMB)

Question: When did the OMB change racial guidelines for the census form?
Answer: 1997

Question: When were the OMB racial directive made mandatory for every government form?
Answer: 2003

Question: What did the OMB vote to allow on the 2000 census?
Answer: participants to select more than one of the six available categories

Question: When did the OMB change federal regulations of racial categories to bar multiple responses?
Answer: Unanswerable

Question: In what year were participants no longer allowed to choose more than one of the six available categories?
Answer: Unanswerable

Question: What was not one of the categories participants could choose on the 2000 United States Census?
Answer: Unanswerable

Question: When did the OMB directive stop being mandatory on government forms?
Answer: Unanswerable

Question: What office is barred from making changes to the census form?
Answer: Unanswerable