Hi Christoph, > When exporting an org document to ODT, the language used for spell checking is > always set to British English. The TOC's name is actually translated to the > language specified in the org document but the spell checking language is not > set correctly. It is particularly weird that it is set to British English > instead of American English because American English is the default pretty > much > anywhere.
This comes with the caveat that I've never used the ODT exporter, but I believe this language setting enters via the default ODT styles file OrgOdtStyles.xml. (I see some country="GB" strings in there.) You could make a copy of this file, change the assumed country, and then use the modified version by setting org-odt-styles-file. Hope that helps, Josiah