$KT is used in place of keytool.

The following manpages all contain the same typo.
jdk/src/bsd/doc/man/keytool.1
jdk/src/linux/doc/man/keytool.1
jdk/src/solaris/doc/sun/man/man1/keytool.1
jdk/linux/doc/man/ja/keytool.1
jdk/solaris/doc/sun/man/man1/ja/keytool.1

I assume that this is a copy/paste error due to copying verbatim from the regression test jdk/test/sun/security/tools/keytool/selfissued.sh

The same typo has migrated into the tech notes:
https://docs.oracle.com/javase/8/docs/technotes/tools/unix/keytool.html