Mine used to be ‘M15’ since Halo 3 all the way through until MCC. Then when Halo 5 came along, it forces you to use 4 characters which sucks, so I had XM15 for a bit but decided to make it MIKE just for the easy callout and XM15 just didn’t have the same feel.
1BUM as 1 Bum plays Halo
EFSF - Earth Federation Space Force, one of the factions in the Gundam franchise. Usually depicted as the good guys, although given the complex nature of Gundam’s factions and plot they aren’t necessarily all that “good” in the various ways they strive to accomplish their goals.
Mine is BAMB for obvious reasons - I had it as BMBO until I got a message from a teammate calling me a -Yoink!- feelsbadman
Mine is TS33. It’s a short version of my gamername.
I don’t want too many people to catch on to mine but sound it out … DVUS… Cuz that’s how I like to play 
haha I want to change my gamer tag to that too
No particular reason. Just being goofy.
Mine is FEAR because my original gamer tag was FeaR mE73
In halo 3 I used Z50 witch attempts to ZSD = Zero Saken Darknite
Halo Reach was M250 = MZSD = Meridian ZSD
Halo 5 its MZXS = Meridian Zero Xion Saken
Previous titles there was no way to enter X, so I used Darknite refering to my Dev Team Darknite Systems XZ
Yo mine is also “JAFA” for jaffa cake, i agree that is is i amazing food 
Though I’m currently using LKWT for obvious reasons, A362 is my most used tag. In the iteration of my character from Halo 3, it was merely Spartan 362. In Halo: Reach when IIIs were a thing (yeah yeah I know Ghosts of Onyx and Noble Team being very specific IIIs), I put an A in front of it. I continued using this.
It no longer really works for the character, given that Spartans now use last names and have identities beyond their numbers. But now I explain it as my character using it in respect to the one that inspired him to become a Spartan, stenciling it onto his armor in tribute. Even his helmet choice is a tribute to them.
And much like my old clan, it can mathematically reach seven. 3+6-2=7. 2+4+0+1=7. 7 is important in Halo. Or at least it was in the original trilogy of Halo, so I always stuck with 362 out-of-character for that reason, as it was fun little coincidence. (2401 was not, and was also a reference to the Monitor of Installation 05, 2401 Penitent Tangent).
Mine is “sick,” I guess my gamertag pretty much explains that.
> 2533274972965199;231:
> Yo mine is also “JAFA” for jaffa cake, i agree that is is i amazing food
Brother? Is that you?
V363–the default tag I was given my first time playing Halo 4.
Mine is WOLF. Im a wolf lover and It represents my clan
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> > Mine is NPRX. I’m sure you can figure it out
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> Ninja Prancing Rainbow Xenomorph’s?
Exactly that
Mine is “NSTY” to represent Nasty, because my friends call me Rick Nasty even though it has nothing to do with my actual name.
ZERE for me, because it’s easy for teammates to identify where I am on the map since it’s just over half of my gamertag haha.
[RUDY]
It’s me name.
My name without the “A”