The first wouldn't work very well if the person wanted to have two pieces of code. Something like this might be intended:

---

I see this in a book:

for (keys %hash) {
    print;
}
[download]

But when I do it like this, it doesn't work

for (key %thisisnotintendedasaseriousquestion) {
    print;
}
[download]

What's wrong?

---

It would be rendered something like (case second box):

---

I see this in a book: But when I do it like this, it doesn't work
Code:

for (keys %hash) {
    print;
}

for (key %somename) {
    print;
}
[download]

---

I'm imagining that the 'Code:' is added automatically. Having code on by default would give something which is somewhat hard to read, for example (case all preformatted):

---

I see this in a book:

for (keys %hash) {
    print;
}

But it doesn't work in my example, please 
<a href="www.somedomain.com/dev/null>look at it here!</a>
[download]

---

Yet I agree that something should be done... Perhaps information on how to display code and escape characters could be at the top of the page before the submission box on the Seekers of Perl Wisdom section only, in hopes that it will be read? (I don't think I'd like seeing it there, so don't consider me in favor of my own suggestion!)