This is the default value for the TIdHTTPServer.SessionTimeOut property.

Id_TId_HTTPSessionTimeOut = 0;

Id_TId_HTTPSessionTimeOut is the default value for the TIdHTTPServer.SessionTimeOut property. This is used in the class definition and the constructor. This is done to prevent problems with Delphi's form streaming mechanism. Changing this value will change the default value for that property.