sed: replace line with file

I have a marker that should be replaced with a file.
I thought this would work, but it does not.

/myre/{
d
r myfile
}

On the other hand this works:

/myre/{
r myfile
d
}

How to understand?

Thanks,
Alan Isaac
(sed newbie)

lmpx.com only provides a reader for public news (NNTP) servers. It is not affiliated with the servers or forums shown here and is not responsible for the content of articles, which is written by their respective authors.