See test jdk/javadoc/doclet/testUseOption/TestUseOption.java

When run with JavadocTester.checkLinks, it generates broken links relating to the use of <Unnamed>

out-2/package-use.html:114: id not found: out-2/package-use.html#<Unnamed>
out-2-html4/package-use.html:109: id not found: out-2-html4/package-use.html#-Unnamed-


Also, see test test/langtools/jdk/javadoc/doclet/testPackageDeprecation/TestPackageDeprecation.java
for similar failures

out-nodepr/package-use.html:113: id not found: out-nodepr/package-use.html#<Unnamed>
out-default/package-use.html:114: id not found: out-default/package-use.html#<Unnamed>