forbidden words error

[domingguss]

https://api.letsvalidate.com/v1/thumbs/?url=https://en.wikipedia.org/wiki/cashmeran&viewport=1200x900&full=true

returns an error:

{
  "error": {
    "code": "016",
    "message": "The url contains forbidden words"
  }
}

The forbidden word seems to be cashmeran, but with capital C it all of a sudden is allowed...

https://api.letsvalidate.com/v1/thumbs/?url=https://en.wikipedia.org/wiki/Cashmeran&viewport=1200x900&full=true