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Understanding Number in Man Page Titles

Strategic angle: A deep dive into the significance of numbers in Unix man page titles, such as sleep(3).

by Editorial Staff|Apr 6, 2026|1 MIN READ|WORLD

The format of man page titles in Unix systems often includes a number in parentheses, which serves a specific purpose in categorizing the documentation.

For example, the title sleep(3) indicates that the sleep command is found in section 3 of the manual, which is dedicated to library functions.

Understanding this numbering system is crucial for developers and system administrators as it enhances the efficiency of navigating and referencing man pages.