Semantic Versioning

deadcode4j adheres to Semantic Versioning 2.0.0¹.

In its current state, deadcode4j considers its public API to be its Maven Plugin capabilities, i.e. the goals & configuration will be (semantically) stable as long as there is no major version change.
If you look at its internals, the names, signatures & semantics of the defined classes (like e.g. de.is24.deadcode4j.analyzer.SimpleXmlAnalyzer) may very well change, as they are NOT considered to be part of the public API (even though they are public classes).

That said, if you simply use deadcode4j as a Maven Plugin, you could even theoretically define its version as [1,2) - however, MNG-2742 prevents you to use version ranges for plugins. :(
If you mess with the code instead, you should stick to a defined version anyway.

¹ deadcode4j did take §2 too lightly in the past. Version 1.5 should have been version 1.5.0 instead. deadcode4j will respect §2 in the future.