No, it is exactly what I need.
Let me explain a bit further.
1. First and foremost. I was a little confused by it. I am not entirely certain what this value is for, and given the 5-6 years I've been using maven, I've never seen it used, nor could I find it well docuemented either. However, what digging I did, the only examples (and tests, from memory) I only ever saw HEAD.
2. Not having the tag present is what I require.
Let me dig into that one for you.
In Jazz SCM terms, a tag is Snapshot (see the extensive doco I put in the SCM provider - working with the release plugin: http://maven.apache.org/scm/maven-scm-providers/maven-scm-provider-jazz/releases.html ). The underlying CLI tool, scm(.exe) is what is used for all Jazz SCM interactions.
The tag operation maps to a "scm create snapshot" operation.
We can not, at this point in time, though the next release V4 due in the next few weeks from what I understand, checkout (load in Jazz SCM terms) we can not directly check out this tag. We need to create (effectively an intermidiate) workspace from the tag/snapshot.
It is this repository workspace that is loaded locally and used to execute the release:perform. ie the same as the svn co .../tag/... command.
So, we are then left with how to specify how to checkout/load the tag/snapshot. ie, the repository workspace.
Yes, we end up with lots of repository workspaces on the server - one for each release performed. These can be deleted. And can also be recreated from the snapshot at any time.
So, effectively, we are at the HEAD of the repository workspace (the one that was created from the tag/snapshot). So in this case, we're at the head of the tag (aka repository workspace).
And this, is why the <tag> item in the section section is returned as null - we don't need it.
And this is correct.
Does this make sense?