[Trane]

Originally Posted by Doitsu

If you're cleaning up a commercial ebook that is protected by a social watermarking scheme, it might contain several of these invisible characters, which you can find with DiapDealer's Shady Characters plugin.

The following customized ShadyCharacters.json file will help you find many commonly used invisible characters:

Spoiler:

{
  "matrix": {
    "zwnj": [
      "0x200C", 
      "‌"
    ], 
    "zwj": [
      "0x200D", 
      "‍"
    ], 
    "shy": [
      "0x00AD", 
      "­"
    ], 
    "zwnbsp": [
      "0xFEFF", 
      ""
    ], 
    "wj": [
      "0x2060", 
      "⁠"
    ], 
    "nbsp": [
      "0x00A0", 
      " "
    ], 
    "thinsp": [
      "0x2009", 
      " "
    ], 
    "zwsp": [
      "0x200B", 
      "​"
    ], 
    "nnbsp": [
      "0x202F", 
      " "
    ]
  }
}

For more information on where to find this file, see the Shady Characters MR topic.

Very interesting! But no, this isn't a commercial book. It's my own work, written in Word, so no watermarking. Would be interesting to run the tool though (but can't at the moment, leaving soon). Thanks for that, though.