The 14 words, usually seen with a swastika and in the form of 14/88.

There's others, but they're usually a co-opt of something common or popular.

A few Behind the Bastards episodes on the neo-nazi perpetuation machine:

Behind the Bastards - How YouTube Became a Perpetual Nazi Machine

And then a multi-part series on the way kids are indoctrinated into these things:

Behind the Bastards - Part One: The Eternal Fascist 🅴
Behind the Bastards Part Two: An American Fascist Faith 🅴
Behind the Bastards - Part Three: The Apostle of Fascism 🅴
Behind the Bastards - Part Four: How To Build An Army 🅴
Behind the Bastards - Part Five: The Hidden Civil War 🅴
Behind the Bastards - Part Six: The Perfect Soldier 🅴
Behind the Bastards - Part Seven: The Digital Reich 🅴

But don't take this as something to freak out about. Keep an open dialogue with your kids, the best way to make sure they don't turn into a racist, fascist or criminal...is to be as big a part of their life as you can without trying to control them. Talk to them about especially the history of racism in Canada, the concerted effort to wipe out First Nations identity and people, and bring them to as many different cultural events as you can. These movements thrive on the Us and Them mentality, if you can teach them that we're all just people, that our similarities outweigh our differences, and that we're culturally healthier with many different people... Well, that'll go a long way.

Edit: formatting is hard early in the morning....

I don't know if it's used in your Region but in Germany 444 is used by neonazis to represent "Deutschland den Deutschen" -> "Germany to the Germans". Maybe there are alliterations like that in your region?

Also, there are certain clothing labels popular in these circles. Lonsdale for example can be worn to only show the "nsda" part as a reference to the NSDAP. There are other examples too.