1 files changed, 29 insertions, 0 deletions
diff --git a/docs/USERGUIDE.md b/docs/USERGUIDE.md
index e2193f0..7f69712 100644
--- a/docs/USERGUIDE.md
+++ b/docs/USERGUIDE.md
@@ -529,6 +529,35 @@ look at what was sent, move it, or empty it without hunting through the tree.
 - Uploads are attributed to the identity the node pinned for that member, and that is what
   decides who may delete the file later — not anything the hub says.
 
+### Downloading a folder as a zip
+
+Any member can take a whole folder: **⋮ → Download as zip** on the folder's row.
+The archive is built in the browser as the files arrive and written straight to
+disk, so a 40 GB folder costs 40 GB of disk and a few megabytes of memory.
+
+- Nothing is compressed. Group content is video, images and archives — already
+  compressed — so deflating would spend CPU on every byte to save nothing, in the
+  same thread that is decrypting.
+- The archive opens as the folder you asked for: a zip of `Holidays/2026` unpacks
+  as `2026/…`, not as a chain of empty parents.
+- Files over 4 GiB, and archives over 4 GiB, use zip64. Anything current reads
+  them; a tool from before 2003 may not.
+- **Firefox and Safari cannot write a download straight to disk** (no File System
+  Access API). There, the archive has to be assembled in memory first, and the
+  browser says so, with the size, before starting. Use Chrome or Edge for a large
+  one.
+
+### Deleting a directory
+
+**⋮ → Delete folder**, for the node operator, from a paired browser (§3). The
+directory must be **empty** — nothing here is recursive, and a folder with
+anything in it is refused before a signature is even asked for. Delete the files
+first, where you can see what you are losing.
+
+Like every privileged action on a node, it is signed with the key the node pinned
+for that browser and refused otherwise: hub membership, or an admin role on the
+hub, grants nothing here.
+
 ### Creating a directory
 
 Any active member can create a directory from the Files panel (**New folder**). It is