This page contains an overview of Duplicate IDs encountered in lists of monuments. These are monument identifiers which appear more than once across the source lists for a given country-language combination. Duplicate IDs are often an indication of copy-paste errors, merged lists, or monuments that have inadvertently been listed twice. All the pages and the statistics are updated on a regular basis by a bot based on the data in the monuments database.

How does it work?

Every night a ErfgoedBot updates the Monuments database with all the lists we have on Wikipedia. While harvesting the monument data, the bot tracks every monument ID it encounters for a given country-language combination. If the same ID appears more than once — whether on the same page or across different pages — it is flagged as a duplicate and reported on the duplicate IDs page, along with a count and links to the source pages where it was found.

How can you help?

Go to the duplicate IDs page (linked below). You'll see a table listing each duplicate monument ID, how many times it occurs and on which pages.

For each duplicate, open the linked source pages and look for the repeated ID. There are a few common scenarios:

• Copy-paste error: A monument was accidentally duplicated when editing the list. Simply remove the duplicate entry.
• Typo in the ID: Two different monuments were given the same ID by mistake. Correct the erroneous ID to the right value.
• Genuinely shared ID: In rare cases the same monument may legitimately appear on multiple list pages (e.g. when a list has been split by region). If the duplication is intentional and correct, no action is needed — but consider whether the lists should be reorganised to avoid confusion.

After you fix a duplicate, the next time ErfgoedBot harvests that list (probably tonight) the entry will be removed from the report.

How can I localise the instructions?

Since the duplicate ID reports are overwritten by ErfgoedBot each time the list is updated you cannot add instructions (or categories) directly to the page. To solve this the /header sub-page is automatically included at the top of the page, if it exists. Thus to add instructions for volunteers in your own language simply create the /header sub-page with the required information.

To localise the message used when there are no more duplicate IDs, simply create a /done sub-page with the desired message.

Overview