It is a URL, page.php, with a query string appended to it.

The query string has "meaning" only to the page.php script. Assuming that it is valid, the variable "Mw" is assigned the value of a literal equal sign, and the variable "s_id" (probably "session ID") is assigned the value "MA==".

These variables have "meaning" only in the context of the page.php script, so that about all you can say about it.

Jim

Just a minor correction, certainly an oversight by a guy like jdMorgan ;)

The GET name/value pairs are actually as follows ...

Name  Value 
----  ----- 
m_id  Mw== 
s_id  MA==

Wow! Very excellent and as always I learn from this site.