From trisher link:-
' In 2016, the working definition and its list of examples was adopted by the IHRA, follow I by many the efforts of Mark Weitzman of the Simon Wiesenthal Center.[8] Weitzman later noted that the EUMC definition was used as there "was not enough time to invent a new one".[9] Following its adoption by IHRA, the working definition has been adopted for internal use by a number of government and political institutions; in historical order: the United Kingdom, Israel, Austria, Scotland, Romania, Germany, Bulgaria, Lithuania and Macedonia.[8] The working definition been formally adopted by eight countries[10] and six of 31 governments whose countries are members of IHRA have formally endorsed or adopted the definition.[11]
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The countries in the IHRA are as follows:-
Argentina
Austria
Belgium
Canada
Croatia
Czech Republic
Denmark
Estonia
Finland
France
Germany
Greece
Hungary
Ireland
ISrael
Ialy
Latvia
Lithuania
Luxembourg
Netherlands
Norway
Poland
Romania
Serbia
Slovakia
Slovenia
Spain
Sweden
Switzerland
United Kingdom United Kingdom
United States of America United States of America
Liaison Countries
Australia
Bulgaria
Observer Countries
Albania
Bosnia and Herzegovina
El Salvador
Moldova
Monaco
Portugal
Former Yugoslav Republic of Macedonia
Turkey
Uruguay
So would it be fair to sum up that the statement " In 2016, the working definition and its list of examples was adopted by the IHRA, ' means the 31 countries who are members of the IHRA agreed to the IHRA definition of antisemitism but also fair to say that whilst the working definition has been adopted for internal use by a number of government and political institutions not all of the 31 countries in the IHRA have not ' formally adopted' the definition.
I have posted to try and put a ' context ' to the numbers involved and how they are being used .