anchor.diff:  YEM,YEM,YEM
   YEM: YEMEN,YEM,YEM
   YEMEN,YEM,YEM
  +Yemen Arab Republic,YEM,YEM
   Yemen (Aden),NULL,*SY
   Yugoslavia,^YG,^YG
   Yugoslavia89-92,^YG,^YG
  
positive.code: US,US,USA
  USA,USA,USA
  USA: UNITED STATES OF AMERICA,USA,USA
  UZB,UZB,UZB
  UZBEKISTAN,UZB,UZB
  VANUATU,VUT,VUT
  
negative.code: Sint Maarten (Dutch part),NULL,SXM
  South Georgia and the South Sandwich Islands,NULL,SGS
  South Vietnam,NULL,*SV
  Republic of Vietnam,NULL,*SV
  South Yemen,NULL,*SY
  Yemen People's Republic,NULL,*SY
  Southern Africa (not specified),?SF,?SF
  SPRATLY ISLANDS [UNDETERMINED],NULL,~PG
  St. Kitts and Nevis,KNA,KNA
  St. Lucia,LCA,LCA
  St. Vincent and Grenadines,VCT,VCT
  St. Vincent and the Grenadines,VCT,VCT
  Sub-Saharan Africa (not specified),NULL,?AH
  Svalbard and Jan Mayen,NULL,SJM
  Syrian Arab Republic,SYR,SYR
  