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.
You may have a beautiful smile, but over the years, repetitive facial movements like smiling and frowning create permanent expression lines. Marionette lines -- so-called because they resemble the cuts that allow the mouth of a puppet to move -- are a common sign of aging due to loss of the skinâs elasticity.