Is > ever necessary?

Question

I now develop websites and XML interfaces since 7 years, and never, ever came in a situation, where it was really necessary to use the > for a >. All disambiguition could so far be handled by quoting <, &, " and ' alone.

Has anyone ever been in a situation (related to, e.g., SGML processing, browser issues, XSLT, ...) where you found it indespensable to escape the greater-than sign with >?

Update: I just checked with the XML spec, where it says, for example, about character data in section 2.4:

Character Data

[14]      CharData       ::=      [^<&]* - ([^<&]* ']]>' [^<&]*)

So even there, the > isn't mentioned as something special, except from the ending sequence of a CDATA section.

This one single case, where the > is of any significance, would be the ending of a CDATA section, ]]>, but then again, if you'd quote it, the quote (i.e., the literal string ]]>) would land literally in the output (since it's CDATA).

Answer 1

You don't need to absolutely because almost any XML interpreter will understand what you mean. But still you use a special character without any protection if you do so.

XML is all about semantic, and this is not really semantic compliant.

About your update, you forgot this part :

The right angle bracket (>) may be represented using the string " > ", and must, for compatibility, be escaped using either " > " or a character reference when it appears in the string " ]]> " in content, when that string is not marking the end of a CDATA section.

The use case given in the documentation is more about something like this :

<xmlmarkup>
]]>
</xmlmarkup>

Here the ]]> part could be a problem with old SGML parsers, so it must be escaped into = ]]> for compatibilities reasons.

Answer 2

I used one not 19 hours ago to pass a strict xml validator. Another case is when you use them actually in html/xml content text (rather than attributes), like this: <.

Sure, a lax parser will accept most anything you throw at it, but if you're ever worried about XSS, < is your friend.

Update: Here's an example where you need to escape > in Firefox:

<?xml version="1.0" encoding="utf-8" ?>
<test>
    ]]>
</test>

Granted, it still isn't an example of having to escape a lone >.