diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in
index e06cf2061b..dd04a05f09 100644
--- a/docs/formatdomain.html.in
+++ b/docs/formatdomain.html.in
@@ -4203,6 +4203,16 @@
attributes: iobase and irq.
Since 1.2.1
+ unassigned
+ For PCI hostdevs, <address type='unassigned'/>
+ allows the admin to include a PCI hostdev in the domain XML definition,
+ without making it available for the guest. This allows for configurations
+ in which Libvirt manages the device as a regular PCI hostdev,
+ regardless of whether the guest will have access to it.
+ <address type='unassigned'/> is an invalid address
+ type for all other device types.
+ Since 6.0.0
+