Under Article 36.1.3 of Taiwan's Trademark Act, a prior
user is someone who has been continuously using an identical or
similar mark on the same or related goods with good intent since
prior to the filing date of a conflicting registered mark. As long
as the use does not exceed the “initial scope,” a prior
user continues to be immune from trademark infringement claims,
hence the “prior user's defense.”
However, the terse language of this article leads to many
questions. Putting aside the meaning of “initial
scope,” when prior users assign or license their trademarks
out after the filing date of a conflicting registered mark, do the
assignees and licensees also have the prior user's
defense?
