Various security-related classes define system properties:

com.sun.security.auth.login.ConfigFile
java.security.auth.login.config

com.sun.security.auth.login.ConfigFile.Krb5LoginModule
sun.security.krb5.principal

java.security.jgss/javax/security/auth/kerberos/package-summary.html
java.security.krb5.realm,java.security.krb5.kdc

java.security.jgss/org/ietf/jgss/package-summary.html
javax.security.auth.useSubjectCredsOnly

The names of these properties are candidates to use the recently-new javadoc tag `{@systemProperty <name>}`, which will cause the names to appear in the main search index.