tspan: simple example

<svg width="600" height="200">
  <g style="font-family:Verdana; font-size:24">
    <text x="50" y="50" style="fill:yellow">
      This document 
        <tspan style="font-weight:bold; fill:aqua">is not</tspan>
      correct
    </text>
  </g>
</svg>