Normal Java resource bundles

In this case the important aspect is the following:

API: java.util.Properties The method does not treat a backslash character, \, before a non-valid escape character as an error; the backslash is silently dropped. For example, in a Java string the sequence "\z" would cause a compile time error. In contrast, this method silently drops the backslash. Therefore, this method treats the two character sequence "\b" as equivalent to the single character 'b'.

MessageFormat rules

Extensively describing rules for embedding " and {. (see javadoc API for MessageFormat)

The special chars ', } and {:

• escape ' with another ' : resulting in '' (double-single quote)
• escape \ with another \: resulting in \ \ (double backslash)
• enclose } with ': resulting in '}'
• enclose { with ': resulting in '{'