proxy feature - rewriting of redirects

Hello,

 

I'm attempting to pull the proxy configuration and am unclear what the method get_rewrite_redirects_mask does and what value is/means.

 

 

GUI Rewrite Redirects value mask value from method

 

choose 0

 

matching 5

 

all 6

 

 

 

is this correct, if so what happened to 1-4?

 

 

thanks.

 

 

Anthony