Once installed and activated, add-on will appear under the Add-ons menu from Google Docs.
Unlike software with built in “show hidden characters” features, Show add-on will actually modify the original document by adding the below characters prior to or in place of the non-visible one. Result is that deleting the visible symbol will not delete the actual non-visible mark, unless you press Delete twice.
Show add-on allows to revert changes by either using Google Docs native undo or History commands, or one of its multiple Hide functions.
Symbols used for non-visible characters are:
⏎ Simple Line Feed (Usually from a Shift-Return)
¶ End of Paragraph (Usually from Return)
❡ End of an empty Paragraph
↡ Page feed (Usually from a Ctrl or Cmd-Return)
▪ Simple Space
→ Tabulation
↓ Vertical Tabulation (now deactivated, as docs encodes these a Line Feeds)
○ No-Break Space
◦ Narrow No-break Space
⊝ Non-breaking hyphens
⫾ Soft hyphens (a.k.a. shy, or syllable hyphen)