From 454f5743821f3d3fdbf4f84b5b4c56b546045470 Mon Sep 17 00:00:00 2001
From: tschmidtb51 <65305130+tschmidtb51@users.noreply.github.com>
Date: Thu, 24 Oct 2024 23:47:08 +0200
Subject: [PATCH] Branches recursion depth

- fixes oasis-tcs/csaf#625
- add original recursion depth of 25 to Guidance of CSAF 2.0
---
 csaf_2.0/guidance/faq.md | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/csaf_2.0/guidance/faq.md b/csaf_2.0/guidance/faq.md
index 023b3dff..c574c084 100644
--- a/csaf_2.0/guidance/faq.md
+++ b/csaf_2.0/guidance/faq.md
@@ -73,3 +73,13 @@ Please see our advise on [CDNs](./cdn.md).
 ### Where can I find a list of all parties that produce CSAF?
 
 Currently, there is no such list available. However, [BSI hosts a list with metadata of known parties](https://wid.cert-bund.de/.well-known/csaf-aggregator/aggregator.json) that produce CSAF files and distribute them in a way that they are automatically retrievable. This list is called a CSAF lister.
+
+## CSAF Internals
+
+### What is the maximum recursion depth allowed in the product tree for `branches`?
+
+Even though it is not formally noted in CSAF 2.0, the recursion of `branches` is limited to 25 repetitions. Therefore, the longest path to a leaf is:
+
+```
+/product_tree/branches[]/branches[]/branches[]/branches[]/branches[]/branches[]/branches[]/branches[]/branches[]/branches[]/branches[]/branches[]/branches[]/branches[]/branches[]/branches[]/branches[]/branches[]/branches[]/branches[]/branches[]/branches[]/branches[]/branches[]/branches[]/product
+```