@Peter_Elderson , everyone, excuse me for replying this in English.
Our MapRoulette challenge includes various checks for the correctness of layer, bridge, and tunnel tags. This is a universal validation/checks we run in multiple countries. It’s possible that the community may find some flagged cases are actually correct per local knowledge, in which case they can be marked as “Not an issue.”
To help mappers better understand the detected issues, we plan to add brief descriptions of the error types to the detailed task instructions in English. This information is also visible in the task properties. We hope this will make it clearer which tagging needs fixing.
‘Suggested fix’ will be vary depending on the type of error detected.