[jQuery] Does jquery's ajax method's identify requests as being ajaxed

[jQuery] Does jquery's ajax method's identify requests as being ajaxed


What I mean to say is, do the native jquery ajax methods append any
parameters that can inform our server side scripts that the request
was submitted using ajax? (e.g. ajax=1)
If not, what could be done to implement this so that we don't need to
repeat ourselves on each and every form?
Thanks