At what situations should I leave out 话 in "~的话"
This sentence seems to use "~的话，..." phrase, but omit the 话. (Let me know if I'm wrong but I proceed with the assumption that it is correct).


I think it omits 人 here; i.e. 有兴趣的 refers to 有兴趣的人 (people who are interested in). Using 人 makes the sentence more formal and polite, without it makes the sentence simpler and the meaning is still clear enough.

BTW ~的 is a common structure used instead of the referred people or things.


  〈代〉 pron. 附着在词或短语之后,构成“的”字结构,代替所指的人或物。如:卖菜的;吃的