Circuit and outlet labeled “House GFI”. Special significance? Okay to tap?

There is a circuit breaker on my (American 2004 built) panel labeled “House GFI”. The one outlet it controls is a GFCI recepticle and is also labeled “House GFI”.
I want to add a few outlets in my basement. Is this a particularly bad or a [...]

How can you tell if an outside electric outlet has GFI protection?

The weather tight exterior box has two spring loaded caps, but has a regular outlet [not GFI] in the box. I assume it is GFI protected but can find no “master GFI breaker” in the box.
Note that house is 31 yrs old and [...]

My gfci wont trip with tester?

I replaced a bad GFi in my house and now it is wired correctly and the it will trip using the test button but will not trip with an external tester. Why would it do this?

Since every GFCI has an integral “test button,” the first and most important [...]