The Structural Classification of Proteins (SCOP) database is a comprehensive resource that classifies proteins based on their evolutionary and structural relationships. The SCOP hierarchy includes levels such as Species, Protein, Family, Superfamily, Fold, and Class. With the rapid growth of new structural data, SCOP has been updated to improve the classification process and facilitate the discovery of new protein relationships. A new update protocol has been introduced, allowing for batch classification of new protein structures based on their detected relationships at the Family and Superfamily levels. This protocol includes a pre-SCOP preview, which provides earlier access to information on new relationships. The impact of worldwide Structural Genomics initiatives on the discovery and growth of protein families and superfamilies has also been discussed. The SCOP database has been updated to accommodate the increasing number of protein structures, with the latest release containing 92,927 domains organized into 3,464 families, 1,777 superfamilies, and 1,086 folds. The database is accessible at http://scop.mrc-lmb.cam.ac.uk/scop. The new update protocol includes a data management system that supports batch analysis of new structures and their relationships, as well as a relational database for storing all SCOP data. The workflow of the update protocol involves sequence clustering, database searches, and manual inspection of results to ensure accurate classification. The new SCOP update system allows for the analysis of unclassified protein structures based on their relationships to already classified structures, rather than by release date. This enables a more efficient classification process. The pre-SCOP system provides a preview of the SCOP developmental version, allowing users to access information on new structural relationships earlier. The SCOP database also includes integrated taxonomy and curated relationships to sequence databases such as Pfam and UniProt. The new developments in SCOP ensure that the database remains up-to-date with the latest structural data and facilitates the discovery of new protein relationships. The database is now able to handle the increasing number of protein structures and provide more accurate classifications. The impact of Structural Genomics on the discovery of protein relationships in SCOP has been analyzed, showing that many new protein families and superfamilies have been identified. The SCOP database continues to evolve to meet the growing demands of the field.The Structural Classification of Proteins (SCOP) database is a comprehensive resource that classifies proteins based on their evolutionary and structural relationships. The SCOP hierarchy includes levels such as Species, Protein, Family, Superfamily, Fold, and Class. With the rapid growth of new structural data, SCOP has been updated to improve the classification process and facilitate the discovery of new protein relationships. A new update protocol has been introduced, allowing for batch classification of new protein structures based on their detected relationships at the Family and Superfamily levels. This protocol includes a pre-SCOP preview, which provides earlier access to information on new relationships. The impact of worldwide Structural Genomics initiatives on the discovery and growth of protein families and superfamilies has also been discussed. The SCOP database has been updated to accommodate the increasing number of protein structures, with the latest release containing 92,927 domains organized into 3,464 families, 1,777 superfamilies, and 1,086 folds. The database is accessible at http://scop.mrc-lmb.cam.ac.uk/scop. The new update protocol includes a data management system that supports batch analysis of new structures and their relationships, as well as a relational database for storing all SCOP data. The workflow of the update protocol involves sequence clustering, database searches, and manual inspection of results to ensure accurate classification. The new SCOP update system allows for the analysis of unclassified protein structures based on their relationships to already classified structures, rather than by release date. This enables a more efficient classification process. The pre-SCOP system provides a preview of the SCOP developmental version, allowing users to access information on new structural relationships earlier. The SCOP database also includes integrated taxonomy and curated relationships to sequence databases such as Pfam and UniProt. The new developments in SCOP ensure that the database remains up-to-date with the latest structural data and facilitates the discovery of new protein relationships. The database is now able to handle the increasing number of protein structures and provide more accurate classifications. The impact of Structural Genomics on the discovery of protein relationships in SCOP has been analyzed, showing that many new protein families and superfamilies have been identified. The SCOP database continues to evolve to meet the growing demands of the field.