For other options requiring an argument, this is stated, i.e.
  -p --priority _positive integer_
  -m --medium-type _type_
in the "modifyrepo (mr)" section of the zypper manpage, or
  -p --priority <integer>
  -m --medium-type <type>
in the "zypper help mr" text.

Not so for the -n --name option. So how is the new name specified?
Interactively, by zypper asking you a question? No. After the repo identifier?
No. Only by specifying the new name immediately after the option, before the
repo (existing) name, alias, # or URL, will the desired result be obtained.

This is the opposite of what happens for "zypper nr" (zypper renamerepo) where
the new alias is specified after the repo's existing alias, name, # or URL.
This is understandable since in "zypper nr" the alias is not an option argument
but IMHO an explicit mention in the docs would be useful.