Character entity references can also have the format &name; where name is a case-sensitive alphanumeric string. For example, Î» can also be encoded as &lambda; in an HTML document. The character entity references &lt; , &gt; , &quot; and &amp; are predefined in HTML and SGML, because, ,  and & are already used to delimit markup. This notably does not include XML's &apos; (') entity.
Lack of facial expression. Lack of facial expression: Introduction. An absence of expression on the face is medically called flat affect. In many cases, the face mirrors the underlying emotions, and the person has limited emotions or various emotional or psychological disorders.
Also possible are physical disorders of the face that limit the ability of the face to show emotion. For example, the partial facial paralysis from Bell's palsy may reduce a person's ability to smile....more Â». Â» Review Causes of Lack of facial expression: Causes | Symptom Checker Â» | Assessment Questionnaire Â».