Word's clipboard hides structured math and list data that most paste handlers delete

A developer building a browser-based exam tool discovered that Microsoft Word places equations on the clipboard twice — once as a flat image and once as structured Office Math Markup Language (OMML). Most paste handlers, including the developer's own, strip the OMML along with other Word-specific XML noise, keeping only the image and discarding the editable math. Word also encodes numbered lists not as HTML list elements but as styled paragraphs, with list membership stored in a CSS property called mso-list and the visible number embedded as literal text. Naive clipboard cleaners preserve that literal number while discarding the styling, producing paragraphs that look like a list but cannot renumber dynamically. The investigation revealed that the order of processing steps matters critically, as stripping conditional comments too early can destroy the only evidence needed to reconstruct list structure.