The database provides the market value of foreign portfolio holdings of U.S. securities by country and by type of security.  Data reflect values at the end of June of each year.

• Values less than $500,000 are reported as zero.
• Foreign holdings of U.S. short-term securities were not measured before 2002.

• Only foreign holdings of U.S. registered debt securities were measured in 1974 and 1978; foreign holdings of U.S. unregistered (bearer) securities were excluded, and thus foreign holdings of US debt are under-counted.

• With the exception of Canada, figures include only private holdings of U.S. equities. 

• Foreign official institutions consist primarily of foreign national government institutions involved in the formulation of international monetary policy, but also include national government-sponsored investment funds and other national government institutions.
• The 1978, 1984, and 1989 surveys reported Belgium and Luxembourg combined as Belgium-Luxembourg.
• Separate reporting for Bosnia and Herzegovina, Croatia, and Slovenia began with the 1994 survey; previously these were reported as part of Yugoslavia.  Yugoslavia became Serbia and Montenegro beginning with the 2002 survey.
• Separate reporting for Anguilla, British Virgin Islands, Cayman Islands, Montserrat, and Turks and Caicos began with the 2000 survey; previously these were reported as the British West Indies.
• Separate reporting for the Isle of Man began with the 1994 survey.  In earlier surveys, Isle of Man was included in Other Europe.
• Separate reporting for Guernsey and Jersey as the Channel Islands occurred prior to 2002.  In prior years, this was also included in the summary cateogry "Other Europe."
• Separate reporting for the Czech Republic and Slovakia began with the 1994 survey.  In earlier surveys, these countries were reported together as Czechoslovakia.
• Separate reporting for French Guiana, Guadeloupe, and French Guiana began in 2002; previously, they were reported as part of French West Indies and Guiana.
• Separate reporting for Armenia, Azerbaijan, Belarus, Estonia, Georgia, Kazakhstan, Kyrgyzstan, Latvia, Lithuania, Moldova, Russia, Tajikistan, Turkmenistan, the Ukraine, and Uzbekistan began with the 1994 survey.  In earlier surveys, these countries were reported together as the USSR.
• Separate reporting for Bonaire, Sint Eustatius, and Saba; Curacao; and Saint Maarten began with the 2014 survey.  In previous years, these countries were reported together as Netherlands Antilles.
• Separate reporting for Guadeloupe and for Saint Martin and Saint Barthelemy began with the 2014 survey.  In previous years, entries for Guadeloupe included Saint Martin and Saint Barthelemy.
• Separate reporting for Kosovo, Montenegro, and Serbia began with the 2014 survey. In previous years, entries for Serbia included Kosovo and Montenegro.
• Separate reporting for Sudan and South Sudan began with the 2014 survey. In previous years, entries for Sudan included South Sudan.
• The cateogry "Other Europe" consists of all European countries other than Austria, Belgium-Luxembourg, Bulgaria, Czechoslovakia, Denmark, Finland, France, German Democratic Republic, Germany, Greece, Hungary, Ireland (1989 only), Italy, Netherlands, Norway, Poland, Portugal, Romania, Spain, Sweden, Sweden, Switzerland, Turkey, United Kingdom, U.S.S.R., and Yugoslavia.
• The category "Other Latin America & Caribbean" consists of all Latin American countries other than Argentina, Bahamas, Bermuda, Brazil, British West Indies, Chile, Colombia, Cuba, Ecuador, Guatemala, Jamaica, Mexico, Netherlands Antilles, Panama, Peru, Trinidad and Tobago, Uruguay, and Venezuela.
• The category "Other Asia" consists of all Asian countries other than Bahrain, China People’s Rep of (Mainland), China Republic of (Taiwan), Hong Kong, India, Indonesia,  Iran, Iraq, Israel, Japan, Korea(South), Kuwait, Lebanon, Malaysia, Oman, Pakistan, Philippines, Qatar, Saudi Arabia, Singapore, Syria, Thailand, and the United Arab Emirates.
• The category "Other Africa" consists of all African countries except Algeria, Egypt, Gabon, Ghana, Liberia, Libya, Morocco, Nigeria, South Africa, and Congo (Kinshasa).
• The category "Other Oceania" consists of all countries in Oceania except Australia.
• The category "African Oil-Exporters" includes Algeria, Gabon, Libya, Nigeria.
• The category "Middle East Oil-Exporters" includes Bahrain, Iran, Iraq, Kuwait, Oman, Qatar, Saudi Arabia, and United Arab Emirates.
• The category "Oil-Exporting Countries" includes Middle East oil-exporters, African oil-exporters, and all other oil-exporting countries; these were not specified for 1978.
• Mainland China excludes Hong Kong, Macau, and Taiwan.