Just a soupçon of thread testing.
Soup Can.
So there.
I attended SoupCon one year.
Nobody told me it was Bring Your Own Crackers. 
Mrs Grass gave the keynote the year i went.
I think of myself as essentially souppro.
It’s important to help rehabilitate ex-soupcons.
Otherwise, they could get very big.
Soupçon?
No, sorry; soup’s off.
You could put them to work in the soup kitchen.
It’s soupçon not boîte de soupe.
Are you just experimenting with “special characters” like letters with special diacritics about them?
If so, here’s this to get you going:
‽ ¿ ¡ ⸮ Ä á à â ä å ç È é è ê ë í î ï ı Ö ó ô ö ō ú ù û ü Ü ū ÿ ñ n̈ ø æ œ Я :Þ
I have plenty more where those came from.
My technique (which I’ve seen other Dopers suggest too): Create a text file on your computer, using Notepad or gedit or whatever editor you like. Collect all your favorite special characters there. You can keep it open in a separate window while you browse the Dope. To include special characters, just cut-and-paste from that window into your Dope edit window.
Saves you the trouble of having to memorize, or look up, all the codes for the characters.
I’ll wait for the sequel -
Soupçon II: The Boil Continues
Just a warning, then. ⸮ does not show up on my computer with only the Windows 7 and Office 2013 default fonts installed. So you may have to come up with something else to use for your backwards sentences, since most people don’t install extra fonts.
If it doesn’t show up for you, how did you know what it was?
For what it’s worth, I see it fine, though I have no idea what I’d use it for.
Sounds plausible enough. I have a fair number of oddball glyphs the probably don’t show up.
For those who can’t see it, ⸮ is a backwards (not upside-down) questions mark. Like Chronos says, I don’t envision what in the world I would use it for. I don’t have any backwards alphabet in my weird-character file, but I do have an entire upside-down alphabet. Who here can see these?
z ʎ x ʍ ʌ n ʇ s ɹ b d o u ɯ l ʞ ɾ ᴉ ɥ ƃ ɟ ǝ p ɔ q ɐ
Here are a few other selected goodies:
“ ” ‘ ’ « » ⎖
— (em-dash)
– (en-dash)
∆ ∫ ∈ ∉ ⊂ ⊆ ⊃ ⊇ ∪ ∩ ⇔ ◯ ⌀ ↓ ↑ ← → ∃ ∨ ∧ ¬ ⊣ ⊢ ⊨ ⊬ Ø ∠ ≅ ∇
- ＋ ± × ÷ ≠ ≈ ~ √ ⇌ 〈 〉 ≥ ∂ ¼ ½ ¾ 𝜋 ℵ ∞
ə ℓ ſ ƒ ϕ ™ ® © £ ¢ €
… § † ‡ ‾ ¶ · • ● ■ ◆ 
▼ □ ★ ☆ ✠ ° ♪ ♬ ♫ ✸ △ ◅ ▓ 。� 
~ | ‖ ¡ ¿ † ‡ ↔ ↑ ↓ ⇈ • ¶ 
# ∞ ‘ ’ “ ” «» ¤ ₳ ฿ ₵ ¢ ₡ ₢ $ ₫
₯ € ₠ ₣ ƒ ₴ ₭ ₤ ℳ ₥ ₦ № ₧ ₰ £ ៛ ₨ ₪ ৳ ₮ ₩ ¥ 
♭ ♯ ♮ © ® ™ ✓ 
☐
Lots more at: http://www.nouilles.info/keyboard_shortcuts.html
More symbols at: Symbol font – Unicode alternatives for Greek and special characters in HTML
And a collection of fancy smilies that Patty O’Furniture posted a while ago:
WTF: (ಠ_ಠ)
Blank stare: (••)
Angry: (ノಠ益ಠ)
Middle finger: (ಠ_ಠ)┌∩┐ (BBQ Pit only, of course)
Smug: (‾⌣‾)
Frustrated: ლ(ಠ益ಠლ)
Whatever: ¯_(ツ)/¯
Confused: 【・ヘ・?】
Evil: ψ(｀∇´)ψ
Shy/ashamed: (//･_･//)
The way Firefox shows unused glyphs is to show a box with the Unicode number inside. So I just looked it up using Google.
I also cannot see these glyphs: , but I know they are U+E024, U+E004, U+E002, U+E025, U+E01F, and U+E02E.
And, yes, Senegoid, those are all the glyphs I can’t see. And, since none of them are valid Unicode, don’t expect them to ever be universal. If those symbols are added, they’ll be given a different code. They appear to be part of the ConScript Unicode Registry, which, as the name implies, is for constructed (aka fake) languages.
Or they may be completely different on your computer, depending on what font they are from.
The first one of those somewhat concerns me, as it is the only one that I might actually care to use on occasion – It is the “Registered Trademark” symbol, a small capital R with a circle around it.
Looking back on the stuff I posted, I see there are TWO of them – One of which, apparently, you see and one of which you don’t. Now I need to know out which one of them is the one that works!
Here is the line they came from: ə ℓ ſ ƒ ϕ ™ © £ ¢ €
First symbol:
Second symbol:
Help me out on the third one in that list too, please, BigT. It’s a medium sized diamond. This, too, appears twice in my file, on this line:
… § † ‡ ‾ ¶ · • ● ■ ◆ ▼ □ ★ ☆ ✠ ° ♪ ♬ ♫ ✸ △ . . .
First one:
Second one:
It also appears along with the playing card suits:
And I just noticed another Registered Trademark symbol: The first one in this group:
® ™ ✓ ☐
Do you see that one?
The last ® is the only registered trademark symbol I can see. I cannot see your second diamond (), nor whatever is, both of which I already linked above and shown are not a part of standard Unicode. They are in the special “private” section of Unicode for special characters that don’t fit.
The other diamond is the exact same character. Both are U+2666.
These are all the exact same symbol, with the same code, and that symbol does not work. It is U+E024, which I already linked earlier, and is part of the private area. Again, only ® works properly.
If you want to check your text file for other duplicates, you can try pasting your symbols in the second text box here.
Also, beware of any characters in the Private Use Area, as they are almost certainly not universal. For quick reference if check any that begin with Also U+10 for six digit codes, U+E for 4 digits, or U+F for 4 and 5 digits.
Thanks, BigT. I’ve updated my little grab-bag character file according to your remarks, deleting the ones you say don’t work.