I can't find anywhere how to create a shortcut for "FLIP HORIZONTALLY"
I do camera scanning for my film negatives which need to be flipped horizontally. I wish there was a shortcut so i can sync this setting from one to dozens of images at a time.
"I wish there was a shortcut so i can sync this setting from one to dozens of images at a time."
As pointed out by Per, you can use the plugin to assign a shortcut to Flip Horizontal. But that doesn't address the rest of your implied question, which is how to sync a flip to dozens of images at the same time.
To sync that change, you don't need a shortcut. Rather, do this:
1. Go to Develop.
2. Do Settings > Enable Auto Sync.
3. In the filmstrip, select all the photos you want to flip.
4. Do Photo > Flip Horizontal.
5. Do Settings > Enable Auto Sync to turn it off (VERY IMPORTANT).