svg:OpacityValueType 

opacity value (e.g., <number>)
 

<alphavalue> | inherit

Simple Type Information

Used By

Attributes svg:PresentationAttributes-FillStroke/@fill-opacity, svg:PresentationAttributes-FillStroke/@stroke-opacity, svg:PresentationAttributes-Gradients/@stop-opacity, svg:PresentationAttributes-Graphics/@opacity, svg:PresentationAttributes-feFlood/@flood-opacity

Source 

<simpleType name="OpacityValueType">
  <annotation>
    <documentation>opacity value (e.g., <number>)</documentation>
    <documentation><alphavalue> | inherit</documentation>
  </annotation>
  <restriction base="string"/>
</simpleType>