Ref. gas meter code req's. for an externally fixed meter. I've just read in another place claims that,

One, 3/4" plugged test tee's are not typically required in the gas pipework immediately after the gas meter. If this is correct, then how do you test the installation?

Two, that after the gas meter another isolator may be fitted that "enables the householder to lock off his gas piping, without interfering with the main shut-off just before the regulator/meter." This is in a single family residence, not a group of apartments or a commercial situation.