git-svn help for authorsfile

In general, all svn projects share the same authorsfile, e.g.

[svn]
authorsfile=/path/to/authorsfile

[svn-remote "project-a"]
   url = http://server.org/svn
   branches = branches/*/project-a:refs/remotes/project-a/branches/*
   tags = tags/*/project-a:refs/remotes/project-a/tags/*
   trunk = trunk/project-a:refs/remotes/project-a/trunk

[svn-remote "project-b"]
   url = http://server.org/svn
   branches = branches/*/project-b:refs/remotes/project-b/branches/*
   tags = tags/*/project-b:refs/remotes/project-b/tags/*
   trunk = trunk/project-b:refs/remotes/project-b/trunk

But if  project-a and project-b has same svn id, map to different
user/email, how do I do?

Can we move authorsfile from svn to svn-remote section ?

Thanks for some help,

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Dongsheng