You are right; you need VTP 3 or transparent mode on VTP 1&2; SWITCH Book says this is limitation of 1&2. I guess when Cisco designed VTP, they did not expect so many Vlans will be needed; You link says extended vlans are "mainly used in service provider networks to allow the provisioning of number of customers". This would be with Private Vlans which also must be set up in Transparent mode.
Vlan ID field is 12 bits long supporting Vlan numbers 1 thru 4094 as specified by IEEE 802.1Q standard. To comply with IEEE standard, Cisco makes "vlan extended range" optional, enabled only when the switch is configured for VTP transparent. I think term "extended vlan" is Cisco-specific term.
Note: there is a difference between range of vlans and max number of supported vlans by a switch; only 4500 and 6500 switches support 4094 numbers of vlans; Other switches like 3560 and 3550 support only 1004 number of vlans.
Edited by martinlo, 24 March 2013 - 06:18 AM.