The Guardian rosetta: the Datablog reference guide to nearly everything

The Guardian datablog reference guide: Ptolomeo's 15th century world map. Photograph: HO/Reuters Photograph: HO/Reuters

• UPDATED: NOW INCLUDING DCLG LOCAL GOV CODES

The actual Rosetta stone is a crucially important ancient Egyptian artifact instrumental in advancing modern understanding of Egyptian hieroglyphic writing.

Data visualisation today can be similarly tricky - country spellings vary wildly, to take one example. The Guardian uses Burma, for instance, while the UN prefers Myanmar. Is it North Korea or the Democratic People's Republic of Korea?

Closer to home, the Press Association will talk about the parliamentary constituency of Hampshire East, while the Office for National Statistics uses East Hampshire. You get the idea.

Recently we've been trying to help our datasets work in the world of linked data - the idea that data needs to be consistently readable across the web. We've started adding ISO country codes to country-level data, for instance and we're going to add in any other codes we can think of to make it easier for you to map our numbers.

So, we've started compiling a reference spreadsheet on Google docs. So far on it we have:

• ISO country codes
• Internet domains
• UK parliamentary constituencies, local authorities and NHS trusts plus their strategic health authorities
• US presidents and UK prime ministers
• British university codes from UCAS
• US state codes

It's just the beginning - we're going to update this all the time. What would be useful for you? Let us know and we'll get the reference.