Slight imprecision in documentation

Hello,

I'm referring to version 4.2.2. I noticed a slight imprecision in the 
documentation at 
"http://www.gnu.org/software/sed/manual/html_node/Regular-Expressions.html".

Using sed to get a list of compressed files from the attached 
"from.htm", I cannot get the substitutions with:

     sed 
's/.*\(http:\/\/xorg.freedesktop.org\/releases\/individual\/lib\/[^"]*\.tar\.(gz\|bz2)\).*/\1/g' 
from.htm >to.htm

Instead, I must use this:

     sed 
's/.*\(http:\/\/xorg.freedesktop.org\/releases\/individual\/lib\/[^"]*\.tar\.\(gz\|bz2\)\).*/\1/g' 
from.htm >to.htm

So, I think the documentation should be updated from:

regexp1|\||regexp2
    Matches either regexp1 or regexp2. Use parentheses to use complex
    alternative regular expressions. The matching process tries each
    alternative in turn, from left to right, and the first one that
    succeeds is used. It is a GNU extension.

to:

regexp1|\||regexp2
    Matches either regexp1 or regexp2. Use escaped parentheses to use
    complex alternative regular expressions. The matching process tries
    each alternative in turn, from left to right, and the first one that
    succeeds is used. It is a GNU extension.


I apologize if I'm wrong.

My Best Regards.


Massimo Masotti - Italy