Help!! Stain on leather jacket

So I noticed a dark streak on the back my Aero Bronco A2 jacket the other day. It wasn't too noticeable so I left it cause i wasn't sure what caused it or what it was. It was about a half inch wide and 2 or 3 inches long. It was bugging me so zi got a cloth and rubbed it a bit and thought it was

Help - removing alcohol stains from lamb leather jacket. What should I do? : r/leatherjacket

Ink Be Gone: Top Methods to Remove Ink from Leather

How to Clean Leather Clothes, Boots, Bags & More

Why Is My Leather Jacket Turning White?

How To Wash a Leather Jacket - Tips From a Leather Crafter

Leather cleaner gave stain on jacket. Anybody know what to do? : r/Leatherworking

How to care for your leather jacket

How to Clean a Leather Jacket the Right Way

Help!! Stain on leather jacket

How to Clean a Leather Jacket (Because You Probably Haven't Since You Bought Yours)

Help!! Stain on leather jacket

How to Condition Leather Jackets

How to Care for a Leather Jacket, According to an Expert

How To Dye A Leather Jacket - The Leather Colour Doctor