Purpose of --subuidname in rootless mode

[kaivol]

When using the --subuidname option in rootless mode, "the user needs to have the right to use the [given] mapping" (source).

I am not particularly familiar with linux subuid stuff, but I can't think of a scenario where a rootless user would have the right to use a subuid map other than his own. As I understand it, the subuid map's name is equivalent to the name of the one and only user who can use it.

Am I missing something, or is the documentation here misleading?

[rhatdan]

I think the range of UIDs have to be contained within the range of UIDs available to the user.

I am guessing something like the following would work.

dwalsh:100000:2000000
dwalsh1:100000:1000000
dwalsh2:100001:1000000