Good Evening,
Here is a very light re-entry within the left frame of a U.S. 1913-15 434 stamp. I don't see anything in Scott Catalogue about it. I'm looking for opinions and making scans and notes of it's existence. The line gets fainter as it goes from bottom to top. Maybe it's common, maybe not - I just don't know. Maybe someone here will spot something more!
Not sure where this topic will lead - but please keep your comments in regards to this stamp only.

Thanks!
Full Stamp

Focus on left frame
