Solo Latch Dialog in PT 7.3?

[MaKoRancid]

I'm reading winter 2006 groundwork on setting up multiple speakers in protools, but I cant find the Solo Latch dialog as stated in the article. Here's what it reads...

"Finally, in the bottom right corner of the Operations Preferences page (Setups > Preferences > Operations tab), choose X-OR (cancels previous solos) as the Solo Latch Preference, as in figure 3. This setting enables you to solo one track at a time, so it can be used like a switching mechanism to change between multiple sets of monitors. (Note: Technically, you can solo multiple tracks with this X-OR setting if you shift-click several solo buttons, but we’re not looking to do that here.)"

Any ideas?
Thanks guys