Key Points: - The judgment discusses the ingredients and test for res judicata under Section 11 CPC, including when it can be decided as a preliminary issue and the necessity/essentiality tests (E.1; E.2; E.3) (!) (!) (!) (!) (!) (!) - It analyzes three prior suits (OS 92/1950-51, OS 748/1968, OS 100/1983) to determine applicability of res judicata to a subsequent suit OS 149/1998, focusing on whether title was conclusively decided and whether the issues are identical or substantially in issue (E.2; E.3; F.53) (!) (!) (!) (!) (!) (!) (!) - It emphasizes the representative nature of suits under Section 92 CPC and how explanations to Section 11 CPC affect res judicata, including binding all interested parties (E.2.1; E.2.2; p_15, p_33-p_35) (!) (!) (!) (!) - The court adopts a twin-test framework (necessity and essentiality) to decide if an issue was directly and substantially in issue and conclusively decided in earlier suits (p_172-p_175; p_180-p_183)

- The judgment holds that OS 149/1998 is not barred by res judicata due to lack of conclusive title determination in OS 92/1950-51 and due to changed circumstances after Wakf notification (MWB 19(11), 1965) (p_50; p_51; p_52; p_53) - It clarifies that a compromise decree may create estoppel by conduct but does not automatically bar subsequent suits on title, as compromise primarily concerned possession/lease rather than title (p_46-p_49) - It concludes that a suit under Section 92 CPC is representative and binds all interested parties, but the title issue must be adjudicated or deemed ancillary to the main relief, depending on entitlement to relief under Section 92 (p_163-p_166)

How to determine res judicata when multiple suits involve representative actors and changing circumstances?