This feature is non-standard and is not on a standards track. Do not use it on production sites facing the Web: it will not work for every user. There may also be large incompatibilities between implementations and the behavior may change in the future.
- If the device's user interface displays the thumb of scrollbars proportionally (that is, sized based on the percentage of the document that is visible), this is 1. Otherwise it's 0.
Accepts min/max prefixes: no