Field guide / Rule 05 — Section marks
The section sign § and the pilcrow ¶ point to a place in a document — and a place is always § and its number, together. Let a line break slip between them and the reference falls apart. The fix is a single invisible character.
The section sign, §, names a numbered section — § 12, and doubled for a span, §§ 12–14. The pilcrow, ¶, names a paragraph — ¶ 4 — and is the older of the two, a scribe’s mark for where a new thought began. Both are pointers: each is meaningless without the number it carries.
Read the space in § 12 as ordinary and your layout engine treats it like any other — a legal place to end a line. So § can strand itself at the right edge while 12 drops to the next line, and for a beat the reader sees a lone section sign pointing at nothing. It is the typographic equivalent of a sentence cut off mid—
The remedy is the non-breaking space: it looks identical, sets identically, but a line is forbidden from breaking across it. Bind § to its number that way and the pair moves as one — either both stay on the line, or both wrap to the next. The same holds for ¶ 4 and for the doubled §§ 12.
Wherever a section or paragraph mark sits before a number with an ordinary space between them, we make that space non-breaking. It is a conservative fix by design: we never insert a space where you left none, never remove one, and never touch a mark that isn’t followed by a digit.
The space is now unbreakable — § and 12 will never land on separate lines.
The doubled sign marks a span of sections — bound to its range the same way.
The pilcrow holds to its paragraph number just as the section sign does.
No number follows, so there is nothing to bind — left untouched.
In short
A section or paragraph mark and its number are one reference, so never let a line break split them. The non-breaking space is the invisible glue — and wherever your text already has the mark, the space and the number, we set that glue for you.
Want to see it on your own text? Convert a document and read the cleanup report — every space we bound is counted there.