Man pages matching name re_syntax in section 3tcl:

re_syntax.3tcl.zh_CN	debian 10 / manpages-zh
re_syntax.3tcl.zh_TW	debian 10 / manpages-zh
re_syntax.3tcl.en	debian 10 / tcl8.6-doc
re_syntax.3tcl.zh_CN	debian 11 / manpages-zh
re_syntax.3tcl.zh_TW	debian 11 / manpages-zh
re_syntax.3tcl.en	debian 11 / tcl8.6-doc
re_syntax.3tcl.zh_CN	debian 12 / manpages-zh
re_syntax.3tcl.zh_TW	debian 12 / manpages-zh
re_syntax.3tcl.en	debian 12 / tcl8.6-doc