Only labels that have been applied to the root export folder and below will be exported. Labels applied above the root export folder will not be included even though they do partially apply to the exported folder.
For example, say “Label1” were applied to $/src and “Label2” were applied to $/src/foo and “Label3” were applied to $/src/foo/sub.
If the export folder was $/src/foo, then Label2 and Label3 would be part of the import, but Label1 would not be.
Note that imported labels cannot contain items that have moved outside the export folder, nor deleted items that were chosen not be imported. If you need labels to contain these items, you will need to be sure to export at a high enough level to include all the items that were ever contained in that label.
Also, the current version will not export any promotions of exported labels. Promotions on any labels will need to be applied manually after the import. Label Promotion support will be added in a future release.