Allow input of special characters in comments and option to display them
Allow special characters in comments such as zero width non-joiner, non-breaking space, non-breaking hyphen, forced line-breaks (not paragraph breaks), etc. and provide an option to display them like InDesign’s “Display Hidden Characters”.
It is an indispensable feature for workflows where copy editors and typesetters use PDF comments to correct texts that will then be imported into InDesign for review.
Furthermore, comment text fields should allow invoking macOS Emoji & Symbols palette (see https://support.apple.com/guide/mac-help/mchlp1560/mac) to easier input.
Antony Upward commented
FWIW Like in Word, Shift+Enter will input a line break in a comment (in Adobe it appears CTRL+Enter also works). Although in comments this works most of the time, sometimes (I haven't figured out the circumstances) as soon as the comment is saved it strips *all* these line breaks.
(FWIW I am using the last sensibly/non-rip-off Adobe Acrobat - DC Pro perpetual license v2015.006.30253 on Windows 10 with all the latest updates/patches installed)