Rule 2256. Counterclaims

(a) An original defendant who asserts against the plaintiff a counterclaim not founded upon the transaction, occurrence or series of transactions or occurrences out of which the original cause of action arose may not join an additional defendant.

(b) An additional defendant may not assert a counterclaim which is not founded upon the transaction, occurrence or series of transactions or occurrences out of which the original cause of action arose.

(c) Rescinded.