Minko schrieb:

Those borderlines form part of different type of administration regions, (countries, provinces, municipalities etc).

My question is not to understand why they are tagged like that, but how to make them render them well into mapsource. Is there some kind of patch I can try out, and where/how can I apply it? Im new regarding patching mkgmap, just using the latest release.

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Chris wrote: what I don't understand: Why is the complex MP processing for borders necessary while we are (mostly) only interested in the border _lines_ ?

It was only a guess, that the MP processing destroys your borderlines. Another reason could be that the borders share another way which is drawn with higher priority so that the borderline is disappearing. Chris