It is an imperfection texture of water stain. This type of water marks can be commonly found on the glass of a bathroom.

The SBSAR allows users to change the size and amount of the stains.

This texture is an imperfection. It is glass stain. When a glass of cold drink is put on a cloth, it will leave a water stain.

There are 6 variations which should be enough for scattering randomness.