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Coding the Post

Wouldn’t it be great if you could just glance at an address and instantly know exactly what part of your area the address was located in? I spent most of the weekend and yesterday writing a proposal for a postcode system for Ireland which would allow you to do just that. It was in response to ComReg’s consultation paper on the topic. A dirtier job than you might imagine, with many numeric, geographic, linguistic and even political twists. But got there in the end.

The full proposal is a little long and answers a lot of questions in the consultation paper about the need for a postcode system in Ireland. However, there’s also a short PowerPoint presentation which summarises the key points of the proposal. It’s only about nine slides long, and I think it’s well worth a look.

The system is designed on the principle that the code has to be useful for many purposes besides delivering mail. That’s why it’s called a ‘placecode’ not a ‘postcode’. It’s designed so that it will be useful for organising public transport, for legal purposes, for publishing census results and for many other activities.

In addition, the numbers are assigned in geographical order, from top-left to bottom right, so that it’s instantly obvious where the code refers to. Have a look at the proposal and you’ll see what I mean.

Download the Presentation “The Placecode System”

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  1. Very interesting. However, I have some points to make:
    1. The use of electoral districts strikes me as a bit iffy since these are liable to change.
    2. How flexible would the system be in catering for institutions/companies that receive large amounts of mail. For instance, in Belgium, the European Commission, European Council, European Parliament, NATO and, I think, Eurocontrol, all have their own postcodes.
    3. Have you thought about backwards compatibility with the Geocode system used by An Post.

  2. Good questions.

    1. It is true that constituency borders for european and local elections are revised every ten years or so. However, The electoral districts (of which the constituencies are made up) change very infrequently and in a very controlled way. The electoral districts system (previously called District Electoral Divisions and Wards) have been in use for more than one-and a-half-centuries, and some of them are still the same as the originals. They have to be kept the same as much as possible in order to allow for meaningful comparisions between censuses.

    2. The answer for institutions, buildings or companies that receive large amounts of mail would be to assign their own streetcode to them. This would allow the mail to be further divided within the building.

    3. Backwards compatibility with Geodirectory is not as difficult as you might imagine, because Geodirectory provides a very flexible and expandable schema. Geodirectory is partly based on imports from the electoral register database. Once the codes are added to the electoral register, the Geodirectory can be automatically updated.

    There’s more detail in the full paper. If you’re interested, let me know and I’ll email you a copy.

  3. Hi,

    Very interesting system. It’s good that we’ll have such a thing in Ireland soon enough hopefully.

    I think the US system has a nifty feature built into it, that allows for an easy way to calculate distances, something like that would be very useful. The amount of websites in the states that have “find your nearest store” type things is amazing, and very very useful.

    Your top/left system doesn’t have that feature naturally, and would need some sort of lookup table.

    Also, when looking at the number system did you just choose to ignore Northern Ireland, or did you leave a possible gap in numbers there?

  4. Hi Antoin,

    Just had a look at the powerpoint slides. Looks like a very good model. Here’s a point you might like to incorporate.

    Since you are using the counties as the basis of the numerical codes, you should use distinct codes for the five cities – Dublin, Cork, Galway, Waterford and Limerick – that are independent administrative entities with the same status as Counties (e.g. Galway City is officially located *beside* Galway County, not *within* Galway County).



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