Adobe has gone nuts! In Lightroom there is a key combination for everything. There is even a key combination for taking the dog out and another one for feeding the cat but only if you have the left panel enabled with… in the develop module…

As far as I have figured out there are 235 key combinations in Lightroom! And these Lightroom key combinations do different things depending on the context.

Task Windows Mac
Go to the Add Keywords field of Keywording panel Ctrl + K Command + K
Set a keyword shortcut Ctrl + Alt + Shift + K Command + Option + Shift + K
Add/remove keyword shortcut from selected photo Shift + K Shift + K
Enable painting Ctrl + Alt + K Command + Option + K
Add a keyword from a keyword set to selected photo Alt + 1-9 Option + 1-9
Cycle through keyword sets Alt + 0 Option + 0
Copy/paste metadata Ctrl + Alt + Shift + C / Ctrl + Alt + Shift + V Command + Option + Shift + C / Command + Option + Shift + V
Save metadata to file Ctrl + S Command + S
Open Spelling dialog box Command + :
Check spelling Command + ;
Open Character Palette Command + Option + T

I think that I have all the 235 Lightroom key combinations that work in Lightroom. The list is by functionality: