Amendment of the Customs Tariff (Preferential Trade Arrangements) (EU Exit)  Regulations 2020  4. —(1) The table in Schedule 1( a ) to the Customs Tariff (Preferential Trade Arrangements) (EU  Exit) Regulations 2020( b ) (which relates to agreements to which those Regulations apply) is  amended as follows.  (2) In a new row to be inserted immediately above the row containing the entry in respect of the  Memorandum of Understanding between the United Kingdom of Great Britain and Northern  Ireland and the Republic of Cameroon concerning the arrangements for applying the effects of the  Interim Agreement establishing an Economic Partnership Agreement between the United  Kingdom of Great Britain and Northern Ireland, on the one part, and the Republic of Cameroon,  on  the  other  part,  signed  28th  December  2020  (“the  Cameroon  Memorandum  of  Understanding”)—  “Interim Agreement establishing an Economic Partnership Agreement between the United  Kingdom of Great Britain and Northern Ireland, on the one part, and the Republic of  Cameroon, on the other part, signed on 9th March 2021.”( c );  “The Cameroon Preferential Tariff, version 1.2, dated 27th April 2021.”;  “The Cameroon Origin Reference Document, version 1.2, dated 27th April 2021.”.  (3) In the row containing the entry in respect of The Cameroon Memorandum of  Understanding—  (4) In a new row to be inserted immediately above the entry in respect of the Free Trade  Agreement between the United Kingdom of Great Britain and Northern Ireland and the Republic  of Singapore signed on 10th December 2020 (“the Singapore Agreement”)—  “Partnership, Trade and Cooperation Agreement between the United Kingdom of Great  Britain and Northern Ireland and the Republic of Serbia, signed on 16th April 2021.”;  “The Serbia Preferential Tariff, version 1.0, dated 27th April 2021.”;  “The Serbia Origin Reference Document, version 1.0, dated 27th April 2021.”.  3 ( a ) Schedule 1 to S.I. 2020/1457 was substituted by regulation 5 of, and Schedule 1 to, S.I. 2020/1657 and was amended by S.I.  2021/241 and 382.  ( b ) S.I. 2020/1457; as amended by S.I. 2020/1657 and S.I. 2021/241 and 382.  ( c )  Upon entry into force or provisional application of the Interim Agreement establishing an Economic Partnership between  the United Kingdom of Great Britain and Northern Ireland, on the one part, and the Republic of Cameroon, on the other  part, signed on 9th March 2021, that Agreement will supersede the Memorandum of Understanding between the United  Kingdom of Great Britain and Northern Ireland and the Republic of Cameroon concerning the arrangements for applying  the effects of the Interim Agreement establishing an Economic Partnership Agreement between the United Kingdom of  Great Britain and Northern Ireland, on the one part, and the Republic of Cameroon, on the other part, signed on 28th  December 2020.  (c) in the third column, above the entry in respect of the Singapore Origin Reference  Document, version 1.0, dated 29th December 2020, insert—  (b) in the second column, above the entry in respect of the Singapore Preferential Tariff,  version 1.0, dated 29th December 2020, insert—  (a) in the first column, above the entry in respect of the Singapore Agreement, insert—  (c) in the third column, above the entry in respect of The Cameroon Origin Reference  Document, version 1.0, dated 29th December 2020, insert—  (a) omit the text in the second column;  (b) omit the text in the third column.  (b) in the second column, above the entry in respect of The Cameroon Preferential Tariff,  version 1.0, dated 29th December 2020, insert—  (a) in the first column, immediately above the entry in respect of the Cameroon  Memorandum of Understanding, insert— 