The curved stitching pattern on the back pockets of Levi's jeans is officially called the Arcuate.
The Arcuate consists of two curved lines stitched across a pocket. It is one of Levi’s oldest and most recognizable design features, helping identify the company’s jeans even when other labels are not visible.
The pattern is sometimes casually called the “double-arc” stitching, but Arcuate is the trademarked term used by Levi Strauss & Co. The shape is also related visually to the later Batwing logo, though the two are not the same thing.
The Red Tab is another separate Levi’s identifier: it is a small fabric tab attached at the pocket seam. Keeping these terms distinct avoids one of the most common mix-ups in Levi’s branding.