In the SAOS 6.17 Planning, Engineering, and Ordering Guide in Table 5-7 "G.8032 logical and virtual rings" (attached) every 39xx and 51xx device has a limit of Virtual Rings that is exactly 2x the number of Logical Rings, except for the 3926m. The 3926m is the only model that is limited to the same number of Virtual Rings as Logical Rings.
Also, in Table 5-8 in the same manual the 3926m and 3928s are limited to the same number of Transit Tunnels as Ingress Tunnels (200), whereas all other models have 2x the number of Transit Tunnels as Ingress Tunnels.
Is this a mistake in the manual? Or is there something fundamentally different about the 3926m model that significantly reduces its number of Virtual Rings and MPLS Transit Tunnels?