What is the difference in spelling, between the two words in the details?

They are the same, letter for letter. So your dictionary has a problem.

@gorillapaws, I think you know the answer, so please give some others a chance before you reply. ;)

@snowberry

My Firefox and Open Office Word spellchecks also marked the spelling for the bottom one as being wrong.

If you have a spellcheck you’d like to use, how about copying and pasting the bottom one into it?

Is it possible that it’s highlighting for wrong usage, rather than wrong spelling.

Or is it only warning about a repeated word?

@janbb @RocketGuy

If you have a browser-provided spellcheck, try copying and pasting the bottom word into the answer box.

Su‎‎‎‎bscription

Subscription

Curious. I just pasted them into the answer box. The “Su” of the second one was highlighted. I reversed them, second one on top, and the whole word on top was highlighted, so it’s not because of repetition. I’m guessing that there’s a special character in there somehow, like perhaps a subscript, that doesn’t show in this interface.

I encountered this paradox earlier today, when trying to deal with some spam “warning” me that “my” Macafee subscription (which I never had) expired.

Same thing in a Word file: the second one, now on top (copied out of my answer box just above), is highlighted as a misspelling.

I then just overtyped the word in question, letter by letter; replacing each copied letter with a typed replacement in the Word file, and it still registers as misspelled.

Curiouser and curiouser.

@Jeruba

You’re on the right track.

One of the bottom characters is wrong.

I had to substitute individual characters from the incorrect spelling into the correct one, until I got the red squiggly underscore.

I deleted the “ion,” and “Subscript” still got the wavy red line. I changed the S to lowercase s and the line remained. I deleted the “Su” and left “script,” and at that point the wavy line went away. So it’s something in the first two letters, and I suspect the u, which is kind of a sneaky vowel. But I still don’t see what’s wrong with it.

@Jeruba

You are getting Phoenix, AZ warm!

I don’t think I would have solved this, if I hadn’t read a post by our favorite simian scholar a few days ago.

I just did your substitution trick, and it did not register as wrong, even when I kept the s and u together as a unit.

I give up now, or I’m going to be distracted for too long from what I’m supposed to be doing.

[Preparing to be impressed]

 
Here’s another puzzle, while we’re at it: you addressed gorillapaws with @ above. Usually it shows red only when the addressed user is above in the thread. But @gorillapaws does not appear here yet. How did that happen then?

Oh. You made a link of ”@gorillapaws” when you typed it in. Very tricky, Brian.

@Jeruba

@You are most correct!

I’ll reveal the answer within the next 24 hours, unless someone gets it right before then.

I can’t seem to reproduce the error by introducing an invisible formatting character, but I do expect it’ll be something along those lines.

I also checked out GP’s recent posts and didn’t find anything relevant. Didn’t go back very far, though. I am supposed to be doing something else.

Su‎‎‎‎bscription

Using the same Su and changing the rest, by backspacing from the end and then typing after the Su. Both have wavy red lines:
Su‎‎‎‎bway
Su‎‎‎‎mmer

Just backspacing from the end, using the error-containing word:

Su‎‎‎‎bscription
Su‎‎‎‎bscriptio – now the wavy red line is under only the Su
Su‎‎‎‎bscripti – same, just the Su, even though this is clearly a misspelled word
Su‎‎‎‎bscript – same
Su‎‎‎‎bscrip – same
Su‎‎‎‎bscri – same
Su‎‎‎‎bscr – same
Su‎‎‎‎bsc – same
Su‎‎‎‎bs – same
Su – same
Su – continuing to backspace, with the Su underlined in wavy red: I backspaced through four invisible characters between the b and the u before the cursor moved to the u and the wavy line disappeared.

I don’t know how to see what’s in there, but something is in there.

That’s it. Stopping now. Stopping.

@Jeruba

Sorry, I didn’t mean for this to become an eyeworm. ;)

Yes, of course you did. Surely you didn’t suppose that posting a puzzle of this sort was meant to help us get on with our pressing business for the day.

@Jeruba

Here’s the post by GP that clued me:

https://www.fluther.com/232376/what-should-i-do-about-these-emails/#quip3802706

There are 4 hidden characters between u and b! Try converting to Symbol, webding, or wingding font.

@RocketGuy, that’s what I said in my next-to-last post above.

I can’t see anything in those suggested fonts, though. The character count in Wingdings is the same. What’s hidden seems to remain hidden.

Copy it into MS Word then change the font. 4 extra characters appear.

@Brian1946 That was definitely mentally-filed under “Neat and Useful”.

@RocketGuy, I see them now, coming at it differently. No idea what those characters are or how they got hidden in there, but I see the divergent symbols.

So if I wanted to do this, how would I do it?

Reverse the process, I guess:
1) type the word in MS Word, change the font to Symbol, Webding, or Wingding.
2) use the Insert Symbol function to add those characters.
3) change font to something normal. The strange characters will become invisible.

@RocketGuy

“There are 4 hidden characters between u and b!”

I knu that the yew was the culprit character, but I thought it was because it was perhaps a Cyrillic “u”.

However, I’m sure you’re right, because I had to hit the Backspace key 5 times to finally delete it.