Once the registration of a type tyre is completed and the date of placing on the market occurs, some changes are not possible anymore and some others remain possible with a reason for the change to be provided in a specific notes field (this can be done either with automatic transfer or by using the GUI). These changes are logged (author, date and time).
For convenience, the accepted reasons are listed:
Correct typo: supplier made a mistake when declaring a value and has to correct it.
Change in standards: the testing standards can be amended and thus some values need to be modified.
Label scale-range change, e.g. as result of amendment of the type approval legislation
Request to change declaration by market surveillance: If an MSA detects an error or mistake that does not need a new registration, it can ask the supplier to modify some values of a registered model.
Correction without changes in declaration: during the lifecycle of a tyre type it might occur, that either the company itself produces more helpful information, or clarification, or that it turns out that for communication with MSA this correction would speed up their understanding (though strictly speaking not legally necessary). Additional information, that does not change in such a case the model, cannot lead to a compulsory change in model number (=no new registration).
Request to change declaration by an external body: Certification Bodies very frequently detect errors in declared data, sometimes typing mistakes, many times performance data that, after testing in an independent laboratory, need correction (“rerating”). Data linked to a product can represent up to dozens of values, and it can happen that one, a few, or more, need adjustment.
More details can be found in the Wiki user guidelines.
Disclaimer: Please note that the European Commission cannot provide a legally binding interpretation of the EU legislation, as this is the sole competence of the European Court of Justice. Any remarks from the European Commission services are without prejudice to the position the Commission might take should related cases arise in a procedure before the Court of Justice.