Wikimedia Bugzilla is closed!

I disagree.  First of all, you can copy easily from the page's actual title rather than the URL.  
Second of all, there are some page names that should actually contain underscores, and we don't 
need to introduce even *more* places where this is difficult or impossible.  And finally, that 
leaves the underscores in the wikitext, where it's still ugly and counterintuitive.

The title was meant to be "Underscores in wikilinks should be changed to spaces
for anchor".  Sorry for the confusion.

First, what pages contain underscores, and how do you create them?  

Second, if this is the case, the software can detect this distinction.  As for
the underscores being ugly, that's true (and I usually avoid them), but it's not
as big a deal.

(In reply to comment #3)
> First, what pages contain underscores, and how do you create them?

None do, but some *should*.  The first one that comes to mind is the redirect [[mod_rewrite]].

> Second, if this is the case, the software can detect this distinction.

Not easily, if at all.

Then your reasoning doesn't make sense to me.  Underscore titles aren't
supported, and I don't see how they could be.  Why should we let that stop us
from improving parsing this way?

Underscore titles are not *currently* supported in the page titles themselves.  Eventually, one 
hopes, we'll get around to allowing underscores along with initial lowercase letters and so on 
(while treating them as more or less canonically equivalent for the purposes of user input, just 
not for display).

Underscore titles *are* currently supported in some places, such as wikilinks, and this should not 
change.

First, initial lowercases are allowed, and even used on wiktionary.  However,
they are disabled on Wikipedia.

If underscore titles were allowed, thousands of current wikilinks would have to
be changed.  One way to avoid that is to rewrite (on save) underscores into
wikilinks into spaces, *until* the ability to have titles with underscores was
created.  That would resolve my concerns while still allowing the possibility of
future underscore titles.

However, this begs the question of what we would use as a URL delimiter in place
of underscores.  Do you have any ideas?  We would either have to come up with an
escape scheme (awkward when manually typing URLs), or sacrifice a different
character.

The link text is the text as written, period.