Custom properties and variables are defined in the properties tag in the pom.xml file
<project>
<properties>
<java.lib1.version>1.0</java.lib1.version>
</properties>
</project>
The property name can be any value. It is referenced by calling ${propertyname}
In this example the property java.lib1.version is defined with the value 1.0.0.RELEASE. The dependency calls the property ${java.lib1.version}, that maven automatically replaces it with the value 1.0.0.RELEASE
<properties>
<java.lib1.version>1.0.0.RELEASE</java.lib1.version>
</properties>
<dependencies>
<dependency>
<groupId>groupId</groupId>
<artifactId>artifactId</artifactId>
<version>${java.lib1.version}</version>
</dependency>
</dependencies>