zsh:1: parse error near `'` after upgrade: does -f also skip /etc/zsh/zshrc.def and /etc/zsh/zlogin?

zsh:1: parse error near `'` after upgrade: does -f also skip /etc/zsh/zshrc.def and /etc/zsh/zlogin?

The goal is to clarify whether invoking zsh with the -f flag completely bypasses all startup files, including the auxiliary files /etc/zsh/zshrc.def and /etc/zsh/zlogin, or whether those files may still be sourced under certain conditions.

Current documentation states that -f disables all startup files, but it does not explicitly mention these auxiliary files, and observed behavior differs between zsh 5.x and 6.x releases, leaving the scope of -f uncertain.

Does -f prevent the loading of /etc/zsh/zshrc.def and /etc/zsh/zlogin in all supported versions of zsh? If those files are still sourced when -f is used, what determines whether they are processed? Are there version‑dependent differences in how -f treats these auxiliary startup files?