With Spring Boot, you can override application properties using command line arguments like so:

java -jar my-boot.jar --my.property.name=value

This, however, fails when you try to pass an empty value:

java -jar my-boot.jar --my.property.name=

java.lang.IllegalArgumentException: Invalid argument syntax: --my.property.name=
  at org.springframework.core.env.SimpleCommandLineArgsParser.parse(SimpleCommandLineArgsParser.java:75)
  at org.springframework.core.env.SimpleCommandLinePropertySource.<init>(SimpleCommandLinePropertySource.java:90)

Since an empty string is a legal value for an application property, there seems to be no good reason to reject command line arguments with an empty value.

A real-world example is Kafka's ssl.endpoint.identification.algorithm which has to be set to an empty string to disable host name verification.