If it will play on a PS4 or Xbox One. If you have a regular Region B player too, and it doesn't work on that but does on the consoles, it is geolocked. If it doesn't play on either, it's A locked, if it plays on both, its Region Free.
Since around late 2014 onwards, Sentai Filmworks introduced a new method to 'avoid reverse importation from Japan' and that is the geolock. A geolock is essentially the disc using a country code rather than a region, so instead of saying it's region locked it is actually geolocked because your player is not set to the United States. This is a weird one to test as some discs are in fact region free but it depends on the authoring.
If you are concerned that you may not be able to play them, basically if you have a PlayStation or Xbox games console you are already set to play them because those are automatically set to the United States country code for some bizarre reason. The standard Blu-ray players do vary on manufacturer however.
Also worth pointing out that some of the earlier geolocked titles (released between December 2014 to March 2015) will only work on PlayStation and a small number of standard Blu-ray players (like Samsung). We have tested them on Xbox One, Seiki U-Vision Region Free Blu-ray players, Panasonic and Toshiba Blu-ray players and they all weren't compatible.
I have a Seiki SR4KP1, which is Region Free. I can change the region coding whenever I please.
And the verdict for Legend of the Galactic Heroes is...
YES.It will play perfectly fine when set to Region B. It's basically Region Free. (Region C doesn't really count- it's just a few countries where importing won't be worth it. Didn't do Region C tests, but who cares)