Changing Web application's context-param and init-param on the fly

Question

As I remember one can change a value of in a web.xml within a Web application on the fly without restarting a Web Server if “reloadable=true” is specified. However, I cannot find documentation confirming this statement particularly for Tomcat.

See example of context-param:

<context-param>  
  <description>This is a context parameter example</description>  
  <param-name>ContextParam</param-name>  
  <param-value>ContextParam value</param-value>  
</context-param>

The same question is about init-param, for example:

<servlet>
<servlet-name>LoginServlet</servlet-name>
<servlet-class>LoginServlet</servlet-class>
<init-param>
    <param-name>jdbcDriver</param-name>
    <param-value>com.mysql.jdbc.Driver</param-value>
</init-param>
</servlet>