From 3c476e43e39dbfcf02c2f16d41ed3134fdf60a4b Mon Sep 17 00:00:00 2001
From: Skylar Ittner <skylar@netsyms.com>
Date: Sun, 5 May 2024 21:21:39 -0600
Subject: [PATCH] Add error response type

---
 Home.md | 33 +++++++++++++++++++++++----------
 1 file changed, 23 insertions(+), 10 deletions(-)

diff --git a/Home.md b/Home.md
index 7136f49..322c417 100644
--- a/Home.md
+++ b/Home.md
@@ -22,16 +22,6 @@ All barcodes shall start with `QSv1` as the first field. The second field shall
 
 ## Data Fields
 
-### Subtype `u`: URL providing the code content
-
-This type allows for smaller and shorter codes by providing a HTTP URL linking to where the barcode's content can be retrieved. The URL shall respond to a `GET` request by serving a Quick Send code with the mimetype `text/plain`. The data shall be served in the same format as it would be if encoded into a barcode directly. If a response is received that is not a valid Quick Send code, the application should handle it the same as scanning an incompatible barcode.
-
-Position | Meaning
----------|--------
-0 | Format header (`QSv1`)
-1 | Subtype header (`u`)
-2 | URL, starting with `http://` or `https://`
-
 ### Subtype `a`: To/From Addresses
 
 Basic to/from address data only.
@@ -119,6 +109,29 @@ Position | Meaning
 43 | EEL/PFC: Use "NOEEI 30.37(a)" for most shipments under $2,500. Otherwise, use the shipment's Automated Export System (AES) Internal Transaction Number (ITN).
 44 | Customs items. See appendix for format.
 
+
+### Subtype `u`: URL providing the code content
+
+This type allows for smaller and shorter codes by providing a HTTP URL linking to where the barcode's content can be retrieved. The URL shall respond to a `GET` request by serving a Quick Send code with the mimetype `text/plain`. The data shall be served in the same format as it would be if encoded into a barcode directly. The HTTP response code shall be `200`. If a response is received that is not a valid Quick Send code, the application should handle it the same as scanning an incompatible barcode.
+
+Position | Meaning
+---------|--------
+0 | Format header (`QSv1`)
+1 | Subtype header (`u`)
+2 | URL, starting with `http://` or `https://`
+
+
+### Subtype `e`: Error response to URL request
+
+This type allows for a server to respond with an error message if a code with type `u` is requested but the request cannot be fulfilled.
+
+Position | Meaning
+---------|--------
+0 | Format header (`QSv1`)
+1 | Subtype header (`e`)
+2 | Error code or reference
+3 | Human-readable error message
+
 ## Appendix
 
 ### Item Types