Character references are numeric or symbolic names for characters that may be included in a SAPI document. They are useful for referring to rarely used characters, or those that authoring tools make it difficult or impossible to enter. You will see character references throughout this document; they begin with a "&" sign and end with a semi-colon (;). Some common examples include the following:

•  "<" represents the < sign. 
•  ">" represents the > sign. 
•  """ represents the " mark. 
•  "å" (in decimal) represents the letter "a" with a small circle above it. 
•  "И" (in decimal) represents the Cyrillic capital letter "I". 
•  "水" (in hexadecimal) represents the Chinese character for water.
  

SAPI character references are discussed in detail later in this section on the “List of SAPI Document Characters”.

According to the XML specification, using a reference is not allowed; you can get a non-breaking space using the   reference.