I. Synthesis.- Some thermodynamic and kinetic effects related to zeolite crystallization.- Organic and inorganic agents in the synthesis of molecular sieves.- Non-conventional crystalline microporous solids.- Molecular engineering of lamellar solids. I. Principles derived from the pillaring of smectite clays.- Molecular engineering of layered structures II. Synthetic approaches to some new pillared derivatives.- II. Characterization.- General overview of the characterization of zeolites.- Sorption of single gases and their binary mixtures in zeolites.- Frequency-response measurements of diffusion of sorbates in zeolites.- Diffraction Studies of zeolites.- Spectroscopic investigations of zeolite properties.- The impact of NMR spectroscopy in molecular sieve characterization I. Low Si/Al ratio materials.- The impact of NMR spectroscopy in molecular sieve characterization II. Investigations of highly siliceous systems.- III. Modification, Reactivity, and Catalytic Activity.- Modification of zeolites and new routes to ion-exchange.- Zeolite framework substitution reliable characterization methods.- Evaluation and tailoring of acid-base properties of zeolites Part 1.- Evaluation and tailoring of acid-base properties of zeolites Part 2.- Catalysis by exchanged cations and zeolite framework sites.- Zeolites in oil refining and petrochemistry.- Composition of the carbonaceous compounds responsible for zeolite deactivation. Modes of formation.- Deactivation of zeolites by coking. Prevention of deactivation and regeneration.- IV. Novel Developments and Vistas.- Molecular sieves with pore openings consisting of more than 12-T atoms.- Chemical bonding in zeolites.- Some aspects of molecular shape-selective catalysis with hydrocarbons in zeolites.- New applications of nonclassical molecular sieve catalysts.- Enzyme mimicking with zeolites.- Microporous materials in organic synthesis.- Concluding Remarks.- List of Participants.