PI
  pcre2build         building PCRE2
  pcre2callout       details of the pattern callout feature
  pcre2compat        discussion of Perl compatibility
  pcre2convert       details of pattern conversion functions
  pcre2demo          a demonstration C program that uses PCRE2
  pcre2grep          description of the <b>pcre2grep</b> command (8-bit only)
  pcre2jit           discussion of just-in-time optimization support
  pcre2limits        details of size and other limits
  pcre2matching      discussion of