A value of NULL indicates that the value is unknown. A value of NULL is different from an empty or zero value. No two null values are equal. Comparisons between two null values, or between a NULL and any other value, return unknown because the value of each NULL is unknown.
Skin Spots on the Face. Most causes of spots on face are harmless. They can be a variety of colors including white, red, black or brown. Common causes include cumulative sun exposure, acne, and skin tags. Keratoacanthoma (hyperkeratosis) is a lesion that grows rapidly, usually on areas exposed to the sun.
Age spots may affect people of all skin types, but they're more common in people with light skin. Age spots: Are flat, oval areas of increased pigmentation; Are usually tan, brown or black; Occur on skin that has had the most sun exposure over the years, such as the backs of hands, tops of feet, face, shoulders and upper back