understanding _=keycode appended to scripts calls


I noticed every call to jquery is appended with a _=keycode (1242204988566 for instance)

is it a prevent cache mechanism ?

should it not be only with debug = true

seems like the dowload of the core scripts happens on every request I make instead of getting the script from the browser cache



where do I look to find an answer by myself

please :)

This is done by jquery…

so this is where i'll look