seed

The seed attribute represents the starting number for the pseudo random number generator of the <feTurbulence> filter primitive.

Only one element is using this attribute: <feTurbulence>

<svg viewBox="0 0 420 200" xmlns="http://www.w3.org/2000/svg">
  <filter id="noise1" x="0" y="0" width="100%" height="100%">
    <feTurbulence baseFrequency="0.025" seed="0" />
  </filter>
  <filter id="noise2" x="0" y="0" width="100%" height="100%">
    <feTurbulence baseFrequency="0.025" seed="100" />
  </filter>

  <rect x="0" y="0" width="200" height="200" style="filter:url(#noise1);" />
  <rect x="0" y="0" width="200" height="200" style="filter:url(#noise2); transform: translateX(220px);" />
</svg>

<svg width="200" height="200" viewBox="0 0 220 220"
     xmlns="http://www.w3.org/2000/svg">
  <filter id="displacementFilter">
    <feTurbulence baseFrequency="0.05" seed="1000"
        result="turbulence"/>
    <feDisplacementMap in2="turbulence" in="SourceGraphic"
        scale="50" xChannelSelector="R" yChannelSelector="G"/>
  </filter>

  <circle cx="100" cy="100" r="100"
      style="filter: url(#displacementFilter)"/>
</svg>