Question about passive (in titles, etc.)

I've seen the passive form being shortened in movie/game/book titles sometimes and I don't know what's the purpose of that.
Instead of the normal される/た + noun after it, I've seen it being written as され + noun. Random example (not a title), (テレビで) 流される暴力 → 流され暴力. From a grammatical point of view, taking away る would turn it into 連用形, but that doesn't connect to nouns, 連体形/終止形 do.
Can anyone explain what this is all about?

Thanks.

Edit: I have 1 more question unrelated to the first. It's about the classical じ aux. verb (I think).
From what I've read it means まい or ないだろう (じの意味 - 古文辞書 - Weblio古語辞典 but I did some searching around and found a lot of 忘れじ(の) translated as "forgotten", shouldn't it be "not forget/forgotten, etc."?
Examples I've found on google - 忘れじの岩石群 → Forgotten Rock Formation, 忘れじのナウシカ・ゲーム→Nausicaä's Forgotten Game, etc.
I've seen a song title - 忘れじの君, what would that mean exactly?
Maybe this is not the same じ aux. verb?

killerinsidee said:

I've seen the passive form being shortened in movie/game/book titles sometimes and I don't know what's the purpose of that.
Instead of the normal される/た + noun after it, I've seen it being written as され + noun. Random example (not a title), (テレビで) 流される暴力 → 流され暴力. From a grammatical point of view, taking away る would turn it into 連用形, but that doesn't connect to nouns, 連体形/終止形 do.
Can anyone explain what this is all about?

Click to expand...

What are the real examples you saw? 流され暴力 doesn't make much sense to me.

killerinsidee said:

Edit: I have 1 more question unrelated to the first. It's about the classical じ aux. verb (I think).
From what I've read it means まい or ないだろう (じの意味 - 古文辞書 - Weblio古語辞典 but I did some searching around and found a lot of 忘れじ(の) translated as "forgotten", shouldn't it be "not forget/forgotten, etc."?
Examples I've found on google - 忘れじの岩石群 → Forgotten Rock Formation, 忘れじのナウシカ・ゲーム→Nausicaä's Forgotten Game, etc.
I've seen a song title - 忘れじの君, what would that mean exactly?
Maybe this is not the same じ aux. verb?

Click to expand...

じ is exactly the classical auxiliary verb you are referring to, and therefore 忘れじの means "unforgettable". Thus, those translations you found are simply wrong.

Thanks for the help.
Sorry for the super late reply, I was away for a bit. I can't remember which title it was, but I found a different one. It's rather vulgar, but it's the only one I can find with the same pattern.
「犯され勇者」- visual novel title.

That's "the noun usage of the -masu stem of a verb + noun", as same as 冷やし中華, 立たされ坊主, 落とし文. The meanings of these words are 冷やした中華, 立たされた坊主（＝子供）, 落とした文（＝手紙）, respectively.