The javadoc documentation list -source as a doclet options.
That's wrong: it's a tool option.
> Then there's a bug in the tool documentation for both 1.4.0 and
> 1.4.1, at least.
> In both of these cases, -source is in the "Options Provided by the
> Standard Doclet" section, not the "Javadoc Options" section.
> The reason this matters is that, for example, the Ant Javadoc task
> actually has code to prevent the use of the -source option when a
> custom doclet is being used. They are mistakenly adhering to the
> buggy tool documentation.