Created attachment 200098 [details] Playground to oberve the bug and play with it. This bug report has some similarity with https://bugs.documentfoundation.org/show_bug.cgi?id=164905, but I think, it is a different one. However I do not understand, why the headings are split in the first example of #164905 and why the page number is given twice there. This bug report relates to Version: 25.8.0.0.alpha0+ (X86_64) / LibreOffice Community Build ID: 4957d832c76598e78a57324dad5b4de7345a33e2 CPU threads: 8; OS: Linux 6.8; UI render: default; VCL: gtk3 Locale: sv-SE (de_DE.UTF-8); UI: de-DE Calc: threaded Tabs which appear in a heading are always replaced by a space. This prevents the user from vertically aligning the text parts of the headlines from a numbering scheme in the headlines themselves by giving the TOC prototypes sufficient hanging indentation. See attached document, which is also a playground to add tabs to headlines and observe the (not existing) result on a generated TOC for the document.