Some AO3 stories have a 'byline' when some is archiving a story for a different author. (OTW is the software AO3 runs on, BTW.)
You can find examples by googling
site:archiveofourown.org "archived by"
The only doc for it in FFF is in defaults.ini:
Code:
## OTW allows users to archive stories they didn't write in certain
## cases. These are indicated by showing a byline such as:
## 'Orig Author [archived by Archivist Author]'
## If use_archived_author is set true (and there's only one author
## listed), author will be set to 'Orig Author' instead of 'Archivist
## Author'. authorUrl will still point to the Archivist Author's page.
#use_archived_author:false