ᐅ Symbol used for piping in our design drawings

Hello everyone,

I have a question regarding a symbol in the draft plans of our house. Unfortunately, there is no explanation for it in the plan legend, and I couldn't find anything about it online either.

What exactly does the symbol (half black, half white with a 45° arrow, rising from left to right) next to the drain "S5" mean?

The toilet and sink apparently share the same drain, which is then located in the wall at the toilet.

I hope someone here can shed some light on this for me.

To me, it looks like two symbols are overlapping.

The arrow indicates ventilation, and the "S/W box" represents a ceiling penetration (possibly with a pipe running through it?).

But I could be mistaken.

It would, of course, be helpful if the entire bathroom with its plumbing could be identified. That would also allow for the process of elimination. I think that is where the ventilation pipe is planned.

Yes, that is the main vent pipe.

Thank you all in advance for your responses!
I have now asked the general contractor (GU) for a joint meeting on this matter to get an answer from him. Let's see when he responds.

Explanation of the diagram:

An upward arrow indicates that a pipe passes upward through the floor slab.
DD = ceiling penetration; 18/18 = dimensions of the penetration.
So, here a pipe starts on this floor and goes upward through the opening in the floor slab.
This will actually be the ventilation pipe, as explained in the notes for DD.

If a downward arrow is drawn, it means a pipe starts here and leads downward.
If the arrow does not break the circle, it marks a pure starting point of a branch or a pipe. In this case, there is usually no ceiling penetration (DD) at that point.
For S5, I would assume that S stands for branch and all branch pipes have been numbered.

Best regards,
Jann