Accessing configuration value from another configuration in the Maven Release plugin - maven

Question

Is it possible in Maven to access a configuration value from another configuration value? For example, in the Release Plugin it is possible to access the project.version key during configuration of the tagNameFormat element. What I would like to do is to then use the tagNameFormat value in another element named completionGoals. See below:
<!-- Snippet from a POM -->
<build>
<plugins>
...
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-release-plugin</artifactId>
<version>2.5.3</version>
<configuration>
<tagNameFormat>${my.pom.property}#{project.version}-${my.pom.property.extra}</tagNameFormat>
<checkModificationExcludes>
<checkModificationExclude>pom.xml</checkModificationExclude>
</checkModificationExcludes>
<completionGoals>clean verify help:evaluate -Dexpression=${tagNameFormat}</completionGoals>
</configuration>
<executions>
<execution>
<id>default</id>
<goals>
<goal>prepare</goal>
<goal>perform</goal>
</goals>
<configuration>
<pomFileName>${release.pom.path}pom.xml</pomFileName>
</configuration>
</execution>
</executions>
</plugin>
...
</plugins>
</build>
Notably, in the above configuration, I can see that the tagNameFormat itself is populated with both the standard POM version property and my own custom property (that incidentally is runtime-defined at the command-line). However, when I try to access the value to define another configuration element, completionGoals, completionGoals appears as a variable placeholder, e.g. "${tagNameFormat}" literally appears in the resulting command. (Verified by running Maven with the -X and -e flags.)
Question(s):
Is it possible to get a populated plugin configuration value from the Maven plugin configuration in the POM?
Am I referring to the tagNameFormat configuration element correctly? How could I do this with the Release plugin?
What does the '#' versus the '$' mean? (Guess: Dynamically versus statically evaluated?)

Answer 1

The only way I'm aware of is to define another POM property:
<property>
<my.pom.property>...</my.pom.property>
<my.pom.property.extra>...</my.pom.property.extra>
...
<myTagNameFormat>${my.pom.property}#{project.version}-${my.pom.property.extra}</myTagNameFormat>
</property>
and to use it accordingly:
<tagNameFormat>${myTagNameFormat}</tagNameFormat>
...
<completionGoals>clean verify help:evaluate -Dexpression=${myTagNameFormat}</completionGoals>
Re 3.: AFAIK, the variable delimiters ${...} and #...# are equivalent and I've never read or heard the contrary. But, to be honest, I've never ever used #...# since I'm used to ${...} from Bash and that's also the only one mentioned on the Filter doc page. (#...# is only mentioned at Escape filtering and such I didn't know that it even exists for a long time.)