Paste Special › Formats copies cell styles and merged areas. It copies no conditional formats,
formulas or validation, so it carries nothing that runs. It still marked the destination
FromFile: copying a formula cell from an opened file and pasting its formats into a new workbook
made that workbook ask before running its own active content.
Formats pastes now count as passive, like values, column widths and notes. The comment and
docs/architecture.md no longer say that pasted formats carry trust.