The Vector Math node's label has a special function used to compute
its label based on the currently selected operation. This operation,
like that of the Math node, is extracted using the "NodeTree"
translation context.
Therefore, in this function it must also use the same context to
translate the label.
In addition, a few node types can have an "Unknown" label if there is
a problem with their internal state (operation, filter type, blending
type). This message can also be translated.
Damien Picard