Wanna annoy a programmer?
Next time you're filling out a form, put a single ÿ at the end.

It's not very commonly used in text and it's 255 in decimal and 0x00FF in hex which feels like something is broken if they go and investigate.

@olafurw
I see that "I've had this pain, and by Harald others will have it too" is alive and well in the world
@olafurw there is an argument to be made for using � (U+FFFD) instead, as it literally is the character used when utf8 decoding libraries silently fails
@olafurw That is evil. I like it!
@olafurw Some people just want to see the world burn, ah?
@olafurw Or, as has happened at work recently, just put in a null byte explicitly
@olafurw To be truly evil put in "[ object Promise ]" in the field.

@olafurw I've always thought that an "@" character in an SMS should break something somewhere sooner or later, but I've never seen it happen myself.

[Its value is zero.]

@TimWardCam @olafurw Twitter (like original SMS linked kind) burned down those bugs decades ago.

@olafurw just rеplаce аll fitting lаtin lеttеrs with similarly lооking Суrilliс lеttеrs.

Like I did in the previous sentence.

@olafurw which reminded me that in the times of #FIDONET the editor would break on Cyrillic “y”, and we had to replace it with latin y everywhere.
@olafurw Classic sign of ascii madness. Make em feel like they’re using uninitialized memory
Here’s one specifically for annoying web developers: replace all your line breaks with
<br>, especially if it’s going to be showing up on a public webpage somewhere
You can also replace your & signs with
&amp;, < with &lt;, and > with &gt;, or even better do all of these when applicable

@olafurw
At least modern forms (and databases) will use UTF-8 encoding where “ÿ” is encoded as 0xc3bf.

So I recommend to go with � which signals “my unicode is broken” (as @gigantos recommended) and “ü” (or something similar) that signals: I am trying to interpret UTF-8 “ü” as Latin1.

@olafurw may I introduce â€~ ?
@olafurw
> if they go and investigate.

bold of you to assume