Over at elisp solves problems, Daniel Gempesaw tell us something I didn’t know: it’s possible to limit the scope of ace-jump-mode. By default ace-jump-mode will find the matching characters in all open windows and frames.
Gempesaw likes to keep related buffers in a frame and wants to limit ace-jump-mode to that single frame. Others want to limit it to the current window, and still others, I suppose, are happy to find all the matches as the default does.
If you’d like to limit its scope, it’s merely a matter of setting an option. Head on over to elisp solves problems for the details.