Every language that doesn't have multi-line comments:

# Of course CodeLang supports multi-line comments!
# This is a multi-line comment!
# How dare you say otherwise!

Still annoys me about Ruby.

It actually does have multiline comments, but they are stupid.

=begin
Look at this shit!
It’s hideous.
And why does it begin with a freaking equals?
=end

__END__
and here is another one.
Everything after this, unto infinity, is ignored
It’s alright, I guess.

But seriously, why can’t we have the standard // and /* ... */ comments? Or maybe ### ... ### if it really really needs to be a hash?

I for one like to know if a line is a comment by looking at that line alone, so when I grep, I don't need to look around for context. So I do
/**
* a comment
**/
This is probably one of the reason against multilines.

@bettercallshao While I agree, it just means we need better (context-aware) tools.

@Root
We need # because of compatibility with unix hash bang (#!/usr/bin/env ruby).

@metamourge that could always be a special rule for the first line, as much as I hate one-off exceptions. Or the interpreter could implement both comment styles. 🤷🏻‍♀️

Let's be glad.
Without that pesky shite polyquines wouldn't be possible

@Root I think that @bettercallshao still uses vi

python has triple quotes, technically not a comment though.

@Wisecrack
That's true, specially if you wanna comment inside of function calls:

func(
arg1,
# inline comments are fine
""" but triple-quotes would be considered a string """
)

I also hate that HTML does not allow comments inside tags

<img <!-- I can't comment here --> src="my_butt.svg">

@eo2875 There is no reason to allow comments inside tags though

@theabbie
Well, not in HTML, but I'm using Vue and Android's XML layout resources which use a heck lot of attributes and I just wanna document why I set some of those arguments the way they are

Not having multiline comments is fine - it is the lack of single line comments wich keeps annoying me in CSS.

Also, comments should start with a single glyph (# prefered because it already is the standard for shell scripts).