multilingual svg

I noticed that the very good and simple code systemlanguage, such in the following example

<switch>
<text x="400" y="500" systemLanguage="en">
  <tspan dy="-50">Love comes</tspan>
  <tspan x="400" dy="200">through the stomach.</tspan>
</text> 
<text x="400" y="500" systemLanguage="de">
  <tspan dy="-50">Liebe geht</tspan>
  <tspan x="400" dy="200">durch den Magen.</tspan>
</text> 
<text x="400" y="500" systemLanguage="es">
  <tspan dy="-50">El amor entra</tspan>
  <tspan x="400" dy="200">por el estómago.</tspan>
</text> 
<text x="400" y="500" systemLanguage="fr">
  <tspan dy="-50">L'amour passe</tspan>
  <tspan x="400" dy="200">par l'estomac.</tspan>
</text>
</switch> 

unfortunately doesn’t work: the browsers don’t recognize it.