Chitons have been excluded because their shells are formed from eight articulated plates and therefore the size of a fixed specimen depends in large part on the preservation method used.

[20] Smallest adult sizes have been listed beginning with a few specimens of Cypraeidae and Strombidae in the first edition,[17] and they now additionally encompass a third family: Marginellidae.

[20] Each print edition has an appendix with an alphabetical listing of entry totals for all private collectors and repositories having ownership of specimens in the registry.

"[20] This "greatest measurable dimension" can be at odds with the standard scientific definition of shell length (from base to apex along the central axis for gastropods, and from the umbo to the ventral margin in bivalves).

Though not included in the registry, they are kept on file for future use in the event that the current record holder is shown to be misidentified or smaller than originally claimed.

These requirements mean that in some cases older or even current malacological literature may include size records which exceed those found in the registry.

These record sizes originally appeared in 1964, in the first edition of Van Nostrand's Standard Catalog of Shells, not as a separate list but interspersed among other species-specific information that made up the bulk of the work.

Unlike previous editions, this third and final installment of the catalog was a ring binder with loose-leaf content, intended as a continually updated resource.

[46] The records were to be maintained "by a special committee of editors through which accurate measurements and correct identifications are verified by knowledgeable conchologists".

[5] The much-expanded fourth supplement incorporated many records from the final (1987) edition of the Lost Operculum Club List of Champions.

[49] Carole Hertz, long-time editor of The Festivus, noted that "a few" records were outdated upon publication as they listed deceased shell owners.

[49] Wagner died in 1992 and, though it was announced the following year that World Size Records would continue to be published,[50][51] no further supplements were completed before Abbott's death in 1995.

The opening paragraph of the first edition set out the project's goals and invited submissions:[1] While the importance of maximum shell size and its role in the overall scheme of Conchology and Malacology is debatable, it remains one point of continual interest among collectors and researchers.

These were published by the Hutsells' company, Snail's Pace Productions, and distributed by Pisor's Marine Shells, both based in San Diego, California.

The text of the fourth edition was completed by Kim and Linda Hutsell and originally planned for release at the 2003 COA convention in Tacoma, Washington,[46] but was greatly delayed and only came out in 2005.

On 2 April 2008, the copyrights to the registry were transferred from Pisor to Jean-Pierre Barbier of Topseashells and Philippe Quiquandon of Shell's Passion.

[2] The online database includes photographs of the listed specimens that have been gathered with the help of collectors, dealers, and institutions such as the Muséum national d'Histoire naturelle in Paris.

[3] Barbier, Quiquandon and Santini moved the print title to an annual publication cycle, starting with the sixth edition in 2009, with Shell's Passion and Topseashells taking over as publishers.

A list of new entries—submitted for inclusion in World Size Records as of November 1987—appeared across the 1988 and 1989 issues of Hawaiian Shell News[61] and also in American Conchologist.

He also welcomed the inclusion of separate entries for infraspecific taxa such as subspecies, varieties, and forms, noting that these "might someday prove to be full species, and maximum sizes might provide evidence as to their status".

[17] Rosenberg identified a minor inconsistency in the grouping of cephalopods (Argonautidae and Nautilidae) and scaphopods (Dentaliidae) with gastropods while listing bivalves separately, opining that "a single alphabetic sequence would be preferable".

While suggesting that errors of the second type would be easier to catch if author citations were included, Rosenberg conceded that this might not be practical due to space limitations.

[17] Comparing around a quarter of the size records from the first edition against shells in the collections of the Academy of Natural Sciences of Philadelphia, Rosenberg found that the latter had larger specimens in some 10% of cases.

[nb 8] Rosenberg concluded: "The Registry would be much more authoritative if it included record sizes from the literature, and I recommend this be done in future editions.

In particular he praised the format and exhaustiveness of the publication, writing that, despite having almost double the entries of its predecessor, the registry was much easier to handle compared with the "heavy and bulky" Standard Catalog of Shells.

He continued: "Many other landmark works by highly respected malacologists are omitted, while articles in periodicals frequently written by amateurs, such as La Conchliglia and American Conchologist, are [not].