What is this 「お忘れ物ございませんように」

Question

For full context, see here: https://www.docdroid.net/XIK9pCk/img-20171020-0001-new.pdf#page=2

The sentence in question is taken from line 24-26:

でも、日本のアナウンスははっきりわかるので役に立つし、「お忘れ物ございませんように」と丁寧な話し方から、日本語のいい勉強にもなります。

My attempt at translation:

However, because I clearly understand the Japanese announcement, it is useful and because it ??「お忘れ物ございませんように」 ?? is a courteous way speaking, it becomes a good lesson in Japanese.

So, I basically can't make any sense of this 「お忘れ物ございませんように」in this context xD By browsing jisho for ございます　I found out that it is the teneigo for "to be, exist". How this ございます relates to ように and お忘れ物　I have no idea. The "it" in my translation is actually redundant, I think. I put it there to make my translation more comprehensible, it shall be a dummy for the for me incomprehensible 「お忘れ物ございませんように」 . But since I'm so utterly clueless about 「お忘れ物ございませんように」 , I might've used my dummy "it" in an inappropriate way (syntactically). If that's the case, I'm sorry ^^

Answer 1

「ございません」 is the respectful form of 「ありません」. So it's equivalent to 「お忘れ物ありませんように」. The 〜ように here is "so/such that", and is omitting any number of acceptable verbs, e.g. (注意)する.

So overall it is just

(Please) make sure there are no forgotten items　→　(Please) make sure you don't leave anything behind

This is a common phrase to hear on trains/subways/etc. in Japan when the vehicle is approaching the next station or stop.