A zero (0) value means no limits on the number of characters that result from expanding entities. A non-zero value specifies the maximum number of characters that can result from expanding entities.

If the reader attempts to read a document that contains entities such that the expanded size will exceed this property, an System.Xml.XmlException will be thrown.

This property allows you to mitigate denial of service attacks where the attacker submits XML documents that attempt to exceed memory limits via expanding entities. By limiting the characters that result from expanded entities, you can detect the attack and recover reliably.