all_export

• automagically export defined variables; not recommended.

global_export

• if set, parameters defined in functions are defined in global contexts as well; I don't like that one.

rcs

• if unset, none of the initialization files are sourced (except for the global zshenv file).
• this also affects history saving: when 'rcs' is unset, the shell history will *not* be saved to $HISTFILE.

global_rcs

• if unset the global 'zprofile', 'zshrc', 'zlogin' and 'zlogout' files are not read.

login

• login shell. this option can be set manually or automatically when the shell is invoked as '-' (actually, when the first character of argv[0] is '-')

The following files will be sourced in this order if they exist, provided the options on the right are set. See also STARTUP/SHUTDOWN FILES in zsh(1).