If you create a job adding a Node parameter (e.g. slavename) with option disallow multi node selection and node eligibility set to All Nodes. If you then select an offline node (e.g. slave4) for the build you'll get a pending build entry in the Build History area on the left on the job's page.
Then within this entry the Node Parameter is specified with
NodeParameterValue: slavename=slave4

If change the job's parameter settings to allow multi node selection and you select two nodes, e.g. one online (e.g. slave 3), one offline (e.g. slave4), you'll also get a pending build entry. But this time the parameter is inconsistently mentioned as
LabelParameterValue: slavename=slave4

My expectation was that in both cases the parameter is given as NodeParameterValue.

This issue has been observed during test development for the acceptance-test-harness project.