Is the MacRoman encoding guaranteed to be supported on all Java SE 1.5+ VMs?

Thanks to people who answered, I could realize I was indeed dealing with files encoded in "MacRoman":

In which encoding is 0xDB a currency symbol?

So I'm wondering: are charsets contained in lib/charsets.jar guaranteed to exist in all the 1.5 JVMs?

http://download.oracle.com/javase/1.5.0/docs/guide/intl/encoding.doc.html

Unlike, say, UTF-8, x-MacRoman is not present in rt.jar but in lib/charsets.jar. I don't understand the difference very well.

Is MacRoman, just like UTF8, guaranteed to be present?

P.S: would be great is someone could create the MacRoman tag.

It's not mandatory. The only charsets which must be supported by every Java implementation are:

• US-ASCII
• ISO-8859-1
• UTF-8
• UTF-16LE
• UTF-16BE
• UTF-16

Sun/Oracle also has a list of the charsets supported by their JRE.