A few Kunming signs

If this is formal Chinese, what is not formal?

BTW what is 諮詢報裝 supposed to mean? I think it means 諮詢+報告+安裝, but is this common? It seems that they can just compress the words whatever way they like.

If this is formal Chinese, what is not formal?

英雄所见略同。

The use of 尊敬 makes it formal to me. :o [i obviously don't have a great mind.]

The use of 單元 here is new to me, never seen that before. Don't you think that 單元門禁 is a bit formal as well? [And no, don't ask me how to phrase it informally, I have no idea.]

The use of 尊敬 makes it formal to me.

There's a difference between formal and using formal Chinese.

But anyway, yes, elements of the notice did use 书面语, for example 未 instead of 没有, but abcdefg said

uses the kind of formal Chinese that...

making it sound as though the Chinese is somehow unexpectedly formal.

报装 is commonly used in mainland, meaning 申请安装. You can google to find out how it is normally used.

What I really meant is that I did not think it sounded like daily colloquial speech.