If the system property `file.encoding` is set on the command line to the name of a charset that is not in the `java.base` module, then the JDK will ignore it and default to UTF-8. In JDK 17 and older, the JDK would attempt to locate the charset, even though it was never supported or documented to change the value of this system property in these releases. Since JDK 18, it is possible to set the system property on the command line to the value `UTF-8` (the default) or `COMPAT`. Setting it to any other value is not defined.