When a name/corporate body in bibliographic record appears to be the same as a LC authority record, it will be automatically linked to this LC authority record for the purpose of authority control.
In case the name/corporate body is not the entity represented in the LC authority record even though they look the same, it needs to be unlinked from the LC authority record by adding subfield $$9 no_linkage.
Example:
100 | 1_ $$a Gibson, Guy $$9 no_linkage |