/usr/share/zsh/5.5.1/help
Edit: /usr/share/zsh/5.5.1/help/export (280B)
export [ name[=value] ... ]
The specified names are marked for automatic export to the envi-
ronment of subsequently executed commands. Equivalent to type-
set -gx. If a parameter specified does not already exist, it is
created in the global scope.