t seems the codes off the cards are not for in game items(Swag), though this can not be 100% confirmed. It seem like the codes will complete the in-game cards, watch the video. Even the codes/cards for the weapons could be to upgrade that item. The weapon/armor could be a specific reward for a completing a specific task that was either left out of the beta or the reward removed to keep it fresh for release(like Beating the strike on hard). So ponder away and get the codes while you can.
-Trading Cards-
1# YKA-RJG-MH9
2# 3DA-P4X-F6A
3# MVD-4N3-NKH
4# TCN-HCD-TGY
5# HDX-ALM-V4K
6# 473-MXR-3X9
7# JMR-LFN-4A3
8# HC3-H44-DKC
9# 69P-KRM-JJA
10# 69P-VCH-337
11# 69R-CKD-X7L
12# 69R-DDD-FCP
13# 69R-F99-AXG
14# 69R-VL7-J6A
15# 69X-DJN-74V
16# 6A7-7NP-3X7
17# 6A9-DTG-YGN
-Sign of the Finite Emblem-
18# 7F9-767-F74
5 more from 9/5:
•FJ9-LAM-67F
•JD7-4CM-HJG
•JDT-NLC-JKM
•JNX-DMH-XLA
•7CP-94V-LFP
EDIT
The reason I think the codes will be for the Grimoire cards, is because they came off physical Grimoire cards(For those of you that didn't know).
Source
If you noticed(From the video)there are several tasks per card. These tasks unlock a preeminent modifier related to that card. If you are able unlock the cards with the codes, that may help you progress at a faster rate. As all the cards seem to be low level encounters, classes and a few weapons/armor; they really would only be of benefit for low levels (1-10). the rest we would have to earn.
Just as an example; say when you redeem the code it completes the entire card. So you get the full benefit of the boost the card provides without having to do all the tasks. Since it would be unlocking a Grimoire card, that could be considered an in game item.
Remember on the weapons/armor when you leveled them, there were a few stages to go through until it was maxed out? If you watch the video, the cards are the same way.
Edit #2
It seems Bungie has updated the site. If you go to your profile under cards, you will see they are for Grimoire cards in game. Not swag.
