[Bug-tar] tar doc question: what is "hard-dereference"; how is it done?

[Linda A. Walsh]

my manpage for tar has:


       --hard-dereference
              follow hard links; archive and dump the files they refer to

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How do you follow a hard link?  Isn't it the same as a regular file
except the link count shows another name linked to the inode as well?
How do you follow it?
What is this switch suppose to do?
(Sorry if this is a dumb question, but I don't get how you'd follow
a hard link vs. not follow it)...