So, what’s the serial type number etched onto the bottom of slabs mean?

Mr_Spud

I just noticed this morning on a couple of new PCGS slabbed coins that I just purchased that there is a number etched onto the bottom of the slabs. It’s hard to see it unless you angle it in the light just right. Anybody know what the numbers mean?

asheland

Probably a layer of verification for slab authenticity.

ricko

I have not seen that yet.... Can you post a picture? And does the number change on each slab? Cheers, RickO

WAYNEAS

@ricko said:
I have not seen that yet.... Can you post a picture? And does the number change on each slab? Cheers, RickO

Ricko, here is one of mine from a 2001 P Kennedy. It reads: JTHWYBK.

I do not know if the code changes on each slab or not but I think that it does.
Wayne

Mr_Spud

Ok, I’ll post a picture of some of the numbers tonight. I only noticed them because I had brought home a UV flashlight that filters out everything except 365nm wavelength for maximum fluorescence to see if the gasket glows funny after reading a post about the gaskets. The gasket didn’t glow very much, but the numbers on the bottom of the slab glowed like crazy. I then looked at the slabs under normal light and you can see the numbers etched on them, but only very faintly and only if angled just right.

Mr_Spud

WAYNEAS picture shows what I’m talking about. I never noticed them before I saw them the other day with the UV light

WAYNEAS

@WAYNEAS said:

@ricko said:

The only way I can think of us knowing if these edge letterings are unique or not is to find a "bulk" dealer who has consecutive certification numbers and have them look at the slab edge letters.
Wayne

Batman23

I noticed these a couple months back. A forum search showed a post about these and no one really having an answer. They have been there for a while now.

asheland

I thought they were all different, but apparently not. Maybe they are per batch?

WAYNEAS

@asheland said:
I thought they were all different, but apparently not. Maybe they are per batch?

Thanks for the update. Are the certification numbers on the labels consecutive or in the general area of being so?
Wayne

asheland

@WAYNEAS said:

@asheland said:
I thought they were all different, but apparently not. Maybe they are per batch?

Thanks for the update. Are the certification numbers on the labels consecutive or in the general area of being so?
Wayne

They are actually!

asheland

WAYNEAS

@asheland said:

Bingo and thanks once again.
Wayne
Edited to add: these letters are slab lot numbers!

jessewvu

I’m a bulk dealer and recently got back a bulk order. I’ll check when I get home and report back

jessewvu

Or maybe I won’t... our host might not want this widely publicized. 🤷‍♂️

Batman23

The search function on this forum really sucks. Here is a previous thread. https://forums.collectors.com/discussion/1009420/interesting-alpha-code-on-slab-edge

Mr_Spud

I think WAYNEAS is probably right, they are probably the empty slab lot numbers

ricko

Well looks like all letters... and some are the same.... might be lot processing identification. Cheers, RickO

asheland

@jessewvu said:
Or maybe I won’t... our host might not want this widely publicized. 🤷‍♂️

I doubt they’d care. I’m interested now. lol

Mr_Spud

I keep calling them numbers, but they are letters. I’m still thinking slab lot numbers even after reading the other thread. I’m going to still take a picture tonight of them under my 365nm UV light, just to show everybody how the letters light up so much.

asheland

I’ve seen them under a black light. It’s cool looking. 👍

jessewvu

Every coin in my bulk order has the same letter code. Lot # for the slab batches makes sense.

Cameonut

Here is a thread I started on this topic a couple of years ago.

https://forums.collectors.com/discussion/1009420/interesting-alpha-code-on-slab-edge#latest

braddick

@WAYNEAS said:

@asheland said:

On an unrelated note: Owning these two coins, what is the distinction between them? In other words, why is one a point higher than the other?

braddick

.

Avocet

This is an interesting discovery- I will check my PCGS slabs too- someone representing PCGS on this forum will hopefully shed some light on the question....

ricko

The question of what these letters mean has been going on for several years here on the forum. To date, I have not seen a conclusive answer. Lots of ideas though... Cheers, RickO

Mr_Spud

Here’s what they look like with the UV light

Mr_Spud

I’m still thinking they are the empty slab lot number codes. At first I thought they had been applied after the coin was slabbed and the slab was sealed because I thought the slab was 2 symmetric halves sealed down the middle, but I found this graphic when I googled PCGS slab that shows the bottom of the slab doesn’t have a seam and it’s not 2 symmetric halves. So the lot number is probably on the empty slab before the coin is inserted

PerryHall

I never noticed them before.

derryb

Great! Another "missing edge lettering" hunt.