diff --git a/README.md b/README.md
index 3d736e9..1d4e06a 100644
--- a/README.md
+++ b/README.md
@@ -38,7 +38,12 @@ Hook files from both directories are collectively parsed and executed in lexicog
 
 For ZFS snapshots intended to save your bacon the `00-*` naming convention is particularly critical. In `/usr/share/libalpm/hooks` you can see for example that when a kernel upgrade happens `60-mkinitcpio-remove.hook` is executed (deleting your existing `vmlinuz-*` kernel image for example at `/boot/vmlinuz-linux`). After that if you're using the `zfs-dkms` package which itself requires `dkms` which in turn installs `71-dkms-remove.hook` this hook removes your ZFS kernel module files. Both the `60-*` and optionally the `71-*` hook (for `zfs-dkms` users) run early due to their naming. If we don't create a snapshot before them we end up creating a snapshot that has not kernel image and no ZFS kernel module files. Out `00-*` hook files are executed first ensuring that a snapshot can safely return you to a working system.
 
-The _trivial_ snapshot chain by default keeps 15 snapshots, the _important_ chain keeps 5. The thought process here is that you will likely not futz around with a kernel every day whereas you may very well install arbitrary packages multiple times a day. Snapshots should keep you safe for a couple of days hence the defaults of 5 and 15 snapshots, respectively.
+By default we identify the active system dataset by doing `findmnt / --noheadings --output source` which for example returns:
+```
+zpool/root/archlinux
+```
+If exactly one source returns that is the exact name of a ZFS dataset in an imported zpool we create a snapshot on it. If no source returns we silently exit. If more than one source returns we raise an error and halt the `pacman` transaction.
+
 
 Snapshots may look like so:
 ```