BiS

I played EQ more on than off from 2001-about 2012 or so and then a few runs here and there since.

Having returned yet again, I saw the term "BiS" popping up all over the place. I had to do some googling to figure out what it meant, so I was just curious - did that term originate in WoW or something? I don't recall it from EQ "back in the day".

Best in slot came from a few MMOs, including WoW.

It really only applies for a handful of items per expansion for each class. Starting in Velious there are so many focus effects and options for various pieces of gear the BIS might vary from toon to toon based on what you already have/still need.

LOL I think you missed the point on what Best in Slot means.
What people do is pick a combo of gear that gives them the focus effects that they need and stats they need and call that set of gear their "Best in Slot" gear. I think you are trying to say that Best in Slot can be very subjective but for some classes, thru parsing and testing, the best in slot is fairly clear though some "Best in slot" gear pieces just aren't too logical for certain classes to get because the effect or stats on the pieces of gear are so far superior to a different class.
For example, in Classic, the white dragonscale cloak or the BCG are both items that were BiS for many classes but are much better suited for very particular classes/sets of classes.

BiS was not a term in use in EQ when I began back in 2000, nor do I remember it used much the first few years, if at all. I remember really hating WoW itemization compared to EQ specifically because there were obvious "best" pieces to wear, whereas in EQ, it seemed like there was so much more flavor with gear and myriad options.

Specific terminology and acronyms vary from server to server. BiS was a common term on my original server and server forums as far back as Kunark. Just like on some servers GTG meant "good to go" (ready). On other servers GTG meant "got to go" (goodbye).

GTG was got to go on Karana, but good to go on Ayonae Ro
I blame the french.

And "kk". I never did understand how that one came to be.

I mentioned in guild that I was in "OS" (Old Sebilis) and some of my guildmates said "what zone is that?" .....

Hey monsieur, the French, for once, are innocent in regards to the evolution of english idiomatisms

And a very american (efficient and pragmatic) website with a "Best in Slot" search function tunable by era for TLP servers, to stay in topic

http://www.eqitems.com/

The thing is, in this era what is BiS basically changes every fight due to resists and stat caps. At least for some classes.

Example: Sarnak Emblazoned Tabard, what many consider a piece of junk is the best in slot BP for rogues on Phara Dar, with the exception of the robe PD himself drops.

Heck I paid 1k for an Anti-Poison Amulet in classic and I use it every single Trak/Sev fight.

Even my "BiS" offhand changes depending on whether or not the mob I am fighting is immune to poison.

The fact that you felt the need to parenthetically explain it pretty much sums it up.

BiS can vary from encounter to encounter. There aren't that many items that you can exclusively wear that equate to BiS in Velious with PotM changing the resist game like it does.

This comment is particularly relevant for mobs with debilitating effects such as fears, stuns or knockbacks where resist checks are more important than having the biggest mana pool, highest AC, most HP or capping STR/DEX/ATK.