Check how they are handled. We should support non-ASCII in advanced queries. From https://cevo-group.slack.com/archives/C01M74N29RD/p1773652139586119 > I tried an Umlaut in advanced queries: > > It works when quoted: https://lapis.cov-spectrum.org/open/v2/sample/aggregated?advancedQuery=division.regex%3D%27Graub%C3%BCnden%27& > It doesn't work when not quoted: https://lapis.cov-spectrum.org/open/v2/sample/aggregated?advancedQuery=division.regex%3DGraub%C3%BCnden&