How to let different programs use same man page

[T o n g <mlist4suntong@yahoo.com>]

Hi, 

What's the trick to have different programs use same man page when 
packaging a Debian package? 

E.g., say I'm packaging gzip, and I want both `man gzip` and `man gunzip` 
goes to the same man file. How can I make it happen? 

Thanks