Concrete guys - Post-tension?

[vectorit]

Question for you concrete guys...

I needed to have something installed in my garage, and the installer needs to anchor it to the floor by drilling down through the slab to install bolts.

He asked "Do you know if the slab is post-tension"?

I have seen the stamps in floors before, warning that the slab was post tension. But in my case being residential, I can not find a stamp in the concrete indicating if it is a post-tension slab.

The installer told me that there is builders in my area, that did do slabs as post-tension but he couldn't tell me all of the builders names.

My house was built in 2001, and from what I have learned so far that right at that year builders starting doing post-tension in my area.

So... If a builder was to do post-tension, are they required to stamp the warning in plain view? like at the threshold of the door way or something?

Is there a way to tell a post-tension slab by looking at some tell tale signs on the borders or something?