Is a boolean property name prefixed by "is" still a valid Java Bean?

I just noticed something I didn't know.

  private boolean isCertified;

  public boolean isCertified() {
    return isCertified;
  }

  public void setCertified(boolean certified) {
    isCertified = certified;
  }

The following getters and setters have been generated by Intellij. By the way, Lombok generate the same kind of getters and setters.

I would have expected something like:

  private boolean isCertified;

  public boolean isIsCertified() {
    return isCertified;
  }

  public void setIsCertified(boolean certified) {
    isCertified = certified;
  }

That's why I usually don't prefix my boolean attributes with ìs, despites the fact I think the property name becomes more readable.

I normally write something like:

  private boolean certified;

  public boolean isCertified() {
    return certified;
  }

  public void setCertified(boolean certified) {
    certified = certified;
  }

So I wonder:

• Having a property named isXXX and a getter being isXXX instead of isIsXXX: is it a valid Java Bean definition?

• Are there any other hidden Java Bean corner cases like that, that I may want to know to improve the code readability?

Thanks