How does Splunk parse german Umlauts?

Hi everyone, I've been confronted with the problem, that the case insensitive search command ```search```, differentiates between ö / Ö, ä / Ä and ü / Ü. My question now is, how does splunk parse the german Umlauts exactly and will it support case insensitivity searches for these characters in the near future? I'm aware of the workaround using ```eval lower() / upper()```, so this question is not about solving the issue, but trying to understand where the issue really originates from. Thanks in advance and best regards, Bojan