Referring to things like unusual command line options as "incantations" has been reasonably common across the history of computer usage at least from the 1970s or so, if not earlier.
If you're familiar with most unix tools, you'd expect that to be --classpath.
If you need more than one addition, do you use a colon separated list (Unix), semicolon (Windows), or repeat it once per option? Does it expand ~ or do you need to
None of this is that hard but if you don't use this all the time it's easy for everyone's soup of almost-but-not-quite similar conventions to blur together and you waste time figuring it out.
In the Java world you have the added problem that the JVM has a legacy convention which doesn't follow any platform standard and the problem that many projects use different conventions so you probably also have a different set of rules for JVM options and the actual program options.
See: http://www.catb.org/jargon/html/I/incantation.html