Rule 4 Application

a defendant claims to be entitled to any contribution, indemnity or other relief over against any other defendant; but a third party notice served on a defendant need not be accompanied by a copy of the civil bill [^f1 (where however, defendants are sued as tort feasors liable in respect of the same damage, they shall be treated as opposite parties and no third party notice need be served under this rule, but any such defendant, if he intends in support of a claim for contribution or indemnity to rely on any contractual right, must furnish particulars thereof in writing to the other parties)];

a third party claims to be entitled to any contribution, indemnity or other relief over against another person not a party to the action (who may be known as a “fourth party”) and

a fourth party or any subsequent party in like case makes a like claim against a person not a party to the action.