Chapter numbering starts from the 2nd sublevel

Hello everyone,
this is my first question here.
I have been using LibreOffice for a long time, but sometimes I need to add chapters in a document in such a way that the first level should be without numbering, and the second starts from the 2nd sublevel. These must be headings so that I can use “table of contents” after that

(Attached foto, because this editor has its own “features”)

To get continuous numbering in level 2 (i.e. a “transparent” level 1 where numbering is concerned), you must put your level 1 paragraph style out of Tools>Chapter Numbering management, otherwise it will always be taken into account in numbering computation.

To avoid restructuring your whole document, I suggest you create a new paragraph style derived from Heading 1:

  • in the style sidepane (F11 if not yet visible, unless you’re under MacOS X, in which case Styles>Manage Styles), with paragraph styles listed, right-click on Heading 1 and New; give it name Heading 1 Unnumbered in Organizer (it will inherit all attributes of Heading 1 so that any change you later make on Heading 1 will be automatically forwarded to it)

  • go to the Outline & Numbering tab

    • leave Numbering style to None
    • set Outline level to Level 1

Restyle all your Heading 1 paragraphs with Heading 1 Unnumbered.

Customize Tools>Chapter Numbering to your liking, notably with Number: None at level 1.

Don’t forget to refresh the TOC if any with a right-click on it and Update index.

EDIT 1 Eliminating numbering display (instead of continuous level-2 numbering)

Apply a specific character style to level-1 numbering:

  • create a Hidden character style with 2-pt size in Font tab, Hidden attribute and Font color White (because Hidden attribute strangely is not honoured) in Font Effects

  • modify Tools>Chapter Numbering as:

    • in Numbering, assign Character style: Hidden
    • in Position, set Numbering followed by: to Nothing

With these settings, the level-1 headings are not exactly aligned to the left margin, but it should be barely noticeable.

To get rid of the level-1 number in the TOC:

  • right-click on the TOC and Edit index
  • in Entries tab, click on Level 1 to modify it
  • click on E# and press Del

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Oops! I didn’t pay sufficient attention to the example. I update my answer.

My answer contains an improvement to try and align the heading as close as possible to the left margin. If you don’t set size to 2 pt, the number is still there white-on-white, causing perhaps an undesired indent.

Heading 1 is associated to a list style and therefore is used to format list items (the Chapter Numbering hierarchy is a list nearly like all others). From experience, adjusting indents (both left and right, though right should not matter with lists) in the paragraph style messes things up. Indent should be adjusted only in the list style, here Tools>Chapter Numbering.

Unfortunately, contrary to paragraph styles, list styles do not allow to send the left indent into the left margin because negative values are prohibited. You must then cheat and make the numbering as small as possible. But this is not perfect. Even at 2 pt, space used by the numbers will become larger and larger when number jumps from 9 to 10 and, in extreme cases, from 99 to 100.

Thanks a lot ajlittoz, this is exactly what I need