501 - Big E (capital E)

Jeans known as "Big 'E' " are generally Levis jeans that were manufactured before 1971.  They are noted by the capitalized E on the rear red tab.  This identifing feature has to be used in conjunction with other identifying features in order to prove authenticity and differences between orgionals and reproductions, and fakes.

  
The famous Big E tab. The (R) on the tab also denotes jeans       Regular more common little e tab.
that were made after 1950 - When the ® started to appear
as Levi's red tab had became a registered trademark.

 There are some more defining points to look for.

-3 digit, 555 or J, J21 stampings on the top of the top button indicate a reproduction jean. 501 stamping usually indicate fakes.

-Singe digit stamping on top button  indicate authentic vintage jeans

-Offset middle belt loop, Single Stitch Rear Pockets and Lemon colored stitching indicate Real Big E Jeans.

- A V-stitch near the top button could indicate either  origional or fakes.