Methodology

Entity identification

Each flag entry is tied to the real-world subject it represents — a country, a US state, an organization — rather than standing alone as a picture. 359 of the 365 entries carry a Wikidata QID and a link to the corresponding Wikipedia article.

Country entries are matched to Wikidata by ISO 3166-1 alpha-2 code rather than by name, because names are ambiguous and codes are not. This is what keeps Georgia the country (Q230) distinct from Georgia the US state (Q1428), and the Republic of the Congo distinct from the Democratic Republic of the Congo.

Adoption dates

285 entries carry an adoption date for the current design, taken from the inception date recorded against the flag item in Wikidata. Where a country has more than one recorded flag item, the most recently adopted is used, on the basis that it represents the design currently in use.

A missing date usually means one of two things: no sourced date exists in the authority record, or the flag is contested and there is no single answer. Afghanistan is an example of the latter.

Descriptions and histories

The written description and history on each flag page are original prose, not copied from reference works. They aim to explain what the design contains, what its elements are generally understood to mean, and how the flag arrived at its present form. Where a symbol’s meaning is disputed or officially unstated, the entry says so rather than picking a version.

Articles

Articles are longer pieces on flag history and design, each bylined by its author. Factual claims — adoption dates, named designers, legislation — should be linked to a source at the point the claim is made, favouring primary records such as constitutions, government gazettes and national archives over secondary summaries.

Images

Flag images are served as SVG and rendered to PNG on request, so the image on a flag’s page and the file you download are the same artwork. Designs are drawn to the official specification where one exists and is public.

Updates and corrections

Every flag page shows when it was last updated. Flags change, official specifications get revised, and reference sources disagree with each other more often than you might expect. If you find an error, let us know — say which page and what you believe the correct information is, and a source if you have one.