Word fields, tables of contents and cross-references: why copy-paste breaks a thesis

Word stores certain things as instructions rather than as characters. A field is a small program: it holds a code, and it displays a result.

`{ TOC \o "1-3" }` says "collect every Heading 1 through 3, with its page number, and show them here". `{ REF _Ref12345 }` says "show the number of the thing bookmarked as _Ref12345". `{ SEQ Figure }` says "this is the next figure in sequence". You see Figure 3; the file contains an instruction that resolves to 3.

This is why figure numbers renumber themselves when you insert a figure in the middle, and why the contents page updates when you press F9. Nothing typed those numbers.

Copy a document out of Word into a text box and paste the result back, and every field arrives as its last displayed value - a literal string. The instruction is gone.

The damage is worse than it looks because the document still appears correct at the moment of paste. The numbers are all there. They are simply no longer connected to anything.

• The contents page freezes. It shows the headings and page numbers from before the rewrite. Edit anything and it silently goes stale, because there is no field left to update.
• Figure and table numbering stops being sequential. Insert a figure and everything after it keeps its old number. Delete one and there is a gap.
• Cross-references become wrong text. "As shown in Figure 3" is now the literal phrase, pointing at whatever is now third - or at nothing.
• Footnotes may be re-anchored or flattened, and citations inserted by Zotero or EndNote lose their field codes, which means the reference list can no longer be regenerated from them.

That last one compounds with the previous article: a manuscript whose citation fields have been flattened cannot be reformatted by the reference manager at all, because the manager no longer knows which item each citation refers to.

For a 1,500-word essay with no fields, none of this matters. For a thesis, it decides whether the work survives.

Any tool that takes pasted text and returns pasted text will do this, regardless of how good the rewriting is, because the round trip through plain text is where the structure is lost - not the rewriting.

This is the reason we process the file itself rather than its text: heading levels, TOC fields, figure numbering, footnotes and the reference list are structural objects, and they never enter the rewrite. After processing, refresh the fields in Word as you normally would and the numbering is intact.

• Toggle field codes before you start. Alt+F9 in Windows Word, Option+F9 on Mac, shows every field as its code. It is the fastest way to see what your document actually contains.
• Update fields before submitting. Ctrl+A then F9 refreshes everything. If the contents page does not change when you do this, it is no longer a field.
• Check a downloaded file the same way. After any tool touches your document, toggle codes and confirm the TOC and figure references are still instructions rather than text.
• Keep the citation plugin fields intact. In Zotero, "Unlink Citations" is irreversible for that copy - it converts every citation to plain text deliberately. A plain-text round trip does the same thing without asking.