Acronyms can be confusing.  The following is a (non-comprehensive) list of BDSM acronyms.

ATM

Ass To Mouth

BDSM

Bondage, Discipline/Dominance, Submission/Sadism, Masochism

B&D

Bondage and Discipline

CBT

Cock and Ball Torture

DM

Dungeon Monitor

DP

Double Penetration

D/S

Dominance and Submission

GWC

Guy With Camera

LGBTQ

Lesbian, Gay, Bisexual, Transgender, and Queer

NSA

No Strings Attached

OTK

Over The Knee (spanking)

PIV

Penis In Vagina

RACK

Risk-Aware Consensual Kink

S&M

Sadism and Masochism

SSC

Safe, Sane, and Consensual

STD

Sexually-Transmitted Disease

STI

Sexually-Transmitted Infection

TNG

The Next Generation (18-30 year olds)

TPE

Total Power Exchange

TV

Transvestite

WIIWD

What It Is We Do (kink behavior)

YKINMK

Your Kink Is Not My Kink