Spoiler
The regiment has already been reserved. There are tons of non claimed regiments to choose from.
https://www.fsegames.eu/forum/index.php?topic=28257.0
You cannot Claim Names or "reserve" them it doesn't matter if another group makes a thread.
What do these rules mean then?: From this thread
1.A name I want to use has already been claimed! Now what?
Pick another, there's plenty of choice.
2.Some guy has a company letter in its regiment's name, that means I can claim the other companies, right?
No. Unless he gives permission, no.
2. If your unit disbands, close down the thread. We will remove threads that have been inactive for a very long time.
Very few if any regiments on this thread are playing the game thus these regiments like the 5thGA haven't been playing Bcof. Have fun with that knowledge also the devs said you couldn't claim names you can join the discord and message one of them.
The rule below states otherwise:
Can I just claim a name by making a thread with its name and no content in it, other then 'Work in Progress'?
If you update the thread within a short period of time, sure. If you just plan on claiming a name and not doing anything with the thread until the game releases, then no.
By association, this means that if you DO make a thread and continually update it, you CAN claim the name. If you don't then, you can't claim the name. So, since Irish is updating his 5thGA thread, he does have a claim to the name, along with all other regimental threads that do update their BCoF threads. This isn't my rule, it's what's pinned on the regimental board. So Law does have to change his regimental name.
Now is anyone gonna actually enforce this? Idk, but the rules are there, I'm just saying.