NSFLB 

Not Safe For Little Bros. Basically something you shouldn't watch when your little brother is in the room.

I was searching 2 girls 1 cup for the first time but I had to wait b/c its NSFLB.

NSFLB by DronerTheMegaBoss June 11, 2011

NSFL

Not Safe For Life; when something is so fucked up that even the raunchiest people would be scarred from it

Dude why would you jerk off to murder hentai? That shit is NSFL

NSFL by Dubiks May 19, 2019

NSFL

Not Safe For Life. Stuff that isn’t appropriate no matter where you are, how old you are, or what time it is. NSFL content is usually gore. Examples of NSFL content include: Goatse, kekma.ga, a lot of videos on Liveleak, 1 Guy 1 Jar, 2 Guys 1 Hammer, etc.

I was on an NSFL content binge last night because I was bored and I had morbid curiosity. I was extremely traumatized and couldn’t sleep at all

NSFL by nlolhere July 20, 2020

Nslb 

North Side Long Beach

I live in NSLB, right by jordan high.

Nslb by long beaach July 22, 2009

NSFTBC 

This word well letters are used on the Blackberry handset, after broadcast messages from your contacts they will normally put NSFTBC which means 'not sorry for the broadcast' and the other one is SFTBC which is 'sorry for the broadcast' so these words are ONLY used on the Blackberry for any Blackberry people who hold this smart-phone.

A girl just died today in a car aciendent send this around to show how much you care. - NSFTBC

Who has the new GHD Straighteners - SFTBC

NSFTBC by K.A18 April 25, 2011

NSFL

Basically, NSFL means “not safe for life”. It’s when something is so scarring that even Satan himself would fear it. A lot of Bait-And-Switch sites use NSFL content for “a joke” when it’s really not. Some of these Bait-And-Switch include, but are not limited to: kekma.ga, dance.swf ,womansalliance.xyz and so on. Those are just some examples

User 1: Hey, Mike! You should check out (bait and switch site)! It’s so cool!

User 2: First, how do you know my name, and second, I’m not clicking that link.

User 1: Just click it!

User 2: Ok, fine. (clicks it) WHAT IN THE LIVING FUC~!

Moral: Don’t click on random links. It could be one of those NSFL sites.

NSFL by wide cat August 18, 2021

NSFL

Really, really messed up content. Like, most doctors and chronically online people cannot handle it. Usually means gore, killings, surgery. etc.

Girl: This pic my husband sent me has me scarred for life! Is it NSFL?
Friend: No crap sherlock, he's a doctor

NSFL by Your local Urban Lexicographer April 27, 2023