I ran into an inconsistency in my study material on VTP when it comes to Client mode. Cisco Network Academy explicitly explains that when a switch is configured as a Client, Vlan information is stored in RAM, not NVRAM (Lan Switching and Wireless Chapter 4 section 4.1.1.4 & 4.1.1.5)
A VTP client only stores the VLAN information for the entire domain while the switch is on. A switch reset deletes the VLAN information.
The CisoPress ICND2 Official Certification Guide explicitly states it IS stored in NVRAM on both Clients and Servers. (page 20-23)
I haven't labed it to check which one is it is. Maybe it's IOS or platform dependent. Though each seem to strictly use the 2960 as their base platform. I'm leaning towards the Cisco Academy of it being in RAM and not Flash/NVRAM. The Academy put a lot of emphasis on it not being in RAM with a "drop in the slot" interactive slides and even a Chapter test question directly stated at clients not having vlan database info stored in Flash, only RAM.. It is kind of odd though because the CiscoPress does also explicitly express that Clients do store their vlan databases in NVRAM and even present a "key topic".
Hummm.. So, which one is it?