Here is where the value is set
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It is a leftover from the introduction of corporate networks and allowed primitive file sharing. Users are supposed to put their name, or network login in that place. That name is used in the "Lock file" generated when you open an Office file. If the file was saved the on the network and someone else tried to open it they would see the user name and know who to contact to get access to the file. BUT, most people do not set the name so it has a generic value, which makes it very annoying instead of useful.
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That name is also used in the "lock file" that is created on the local drive when you.
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The value is saved as part of the file when it is initially created. So, it is not surprising that old files have useless values.
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