patch 8.1.1838: there is :spellwrong and :spellgood but not :spellrare commit https://github.com/vim/vim/commit/08cc374dabd2a02785129fa1c0100f7745c244ad Author: Bram Moolenaar <Bram@vim.org> Date: Sun Aug 11 22:51:14 2019 +0200 patch 8.1.1838: there is :spellwrong and :spellgood but not :spellrare Problem: There is :spellwrong and :spellgood but not :spellrare. Solution: Add :spellrare. (Martin Tournoij, closes https://github.com/vim/vim/issues/4291)

/* spellfile.c */
slang_T *spell_load_file(char_u *fname, char_u *lang, slang_T *old_lp, int silent);
void suggest_load_files(void);
int spell_check_msm(void);
void ex_mkspell(exarg_T *eap);
void mkspell(int fcount, char_u **fnames, int ascii, int over_write, int added_word);
void ex_spell(exarg_T *eap);
void spell_add_word(char_u *word, int len, int what, int idx, int undo);
/* vim: set ft=c : */