Maven: property substitution not done for /project/version tag of pom?

http://maven.apache.org/pom.html#Properties says property "values are accessible anywhere within a POM".

Should this read "are accessible in most places within a POM"?

I can specify the version of a dependency no problem like so:

<dependency>
    <groupId>junit</groupId>
    <artifactId>junit</artifactId>
    <version>${junit.version}</version>
    <scope>test</scope>
</dependency>

But what about the version of the project itself like so:

<project xmlns="http://maven.apache.org/POM/4.0.0" ...>

    <modelVersion>4.0.0</modelVersion>
    <groupId>com.mycompany.app</groupId>
    <artifactId>my-app</artifactId>
    <version>${myversion}</version>

    <properties>
        <myversion>8</myversion>
    </properties>

    <modules>
        <module>alpha</module>
        <module>beta</module>
    </modules>
    ...

If I try this <version> will not take the value 8. Here I've defined ${myversion} in the pom but the same seems to be the case if I specify -Dmyversion=8 on the command line.

If one of the modules specifies its parent with a hardcoded version number like so:

<parent>
    <groupId>com.mycompany.app</groupId>
    <artifactId>my-app</artifactId>
    <version>8</version>
</parent>

When I try to build then when maven comes to look at the module's pom it will say it cannot find the given parent pom with version 8.

However if I hardcode version in the parent to 8 as well, rather than using ${myversion}, then everything works fine.

So it seems to me that property substitution does not happen for the /project/version tag of the parent pom.

Is this the case or is there some other explanation for what I seem to be seeing?

Regards,

/George