ISO 4, also known as “Information and documentation — Rules for the abbreviation of title words and titles of publications,” is a globally recognized standard defining a consistent method for abbreviating titles of serial publications like scientific journals. The International Organization for Standardization (ISO) has designated the ISSN International Centre as the registration authority overseeing ISO 4 compliance. This standard includes the List of Title Word Abbreviations (LTWA), providing standardized abbreviations for common words found in serial titles. The most recent update to ISO 4 was in 1997, reflecting its ongoing relevance since its initial publication in 1972 (ISO 4:1972), followed by editions in 1984 (ISO 4:1984) and 1997 (ISO 4:1997).
One of the primary applications of ISO 4 is in shortening the names of scientific journals using the LTWA. For example, according to ISO 4 guidelines, the Journal of Biological Chemistry becomes J. Biol. Chem., while the Journal of Polymer Science Part A is abbreviated as J. Polym. Sci. A (note that capitalization is not specified). The standard emphasizes that full stops are used exclusively for indicating an abbreviation, with the option to omit them in contexts where punctuation is limited.