Thanks for mentioning the problem. However, I found the proposed rewrite 
to be more confusing than the original. I think part of the problem is 
that this is not really the place to explain octal notation; any reader 
who doesn't know octal before reading the manual is not likely to 
understand it even with the proposed rewrite. I think we should just 
give up and assume that the reader knows octal (if they don't they 
should be using symbolic modes). That being said, we could briefly give 
an example of how the individual bits are combined into an octal digit, 
and rearrange the description to make it more intuitive. I installed the 
attached patch to try to improve things.

I also merged Bug#31043 with Bug#29069 since they're the same topic.