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The set of allowed characters should be determined by the fact that the connector name is part of the url in a rest call to update the config or delete the connector, so we should take care
to allow only characters that can be "legally" used within urls - however it turns out that this is not an entirely easy distinction. After looking at a few stackoverflow threads(here, here & here) as well as RfCs 1738, 2369 2396 and 3896 my understanding is the following.
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