This way you can make up a dozen message screens, and use whichever one you want.
I had a hard time grokking this at first, I was thinking you could create a little table of messages for quick insertion into the Message ShowScreen (trying to use proper lexicon) - apparently what this is is actually more powerful.

If what I am assuming is going on is the case, then what you type in the prompt box when using this feature gets assigned to the [msg] meta tag, and any ShowScreen you could conceptually create with a text box that included the [msg] tag would then show this on display. (when you select the ShowScreen from the Video menu) - Hopefully, the display of the tag doesn't wipe it's contents, so you could display it repeatedly throughout the show, without having to re-enter text. (I don't think you could do this with the "Screen Message" option, I think it wiped the tag on execution.) This is a really sweet feature!!! THANKS!! - Now I don't need to do wacky file name changes prior to shows for different venues, if I have a custom Message ShowScreen for each venue (and I do.)

Also, I'm noting that if you have a Custom Screen Message set, and then you use the old Screen Message option, the Custom Screen Message is preserved (not overwritten) for the next time you want to click the Message ShowScreen. (Interesting, because I'm thinking they use the same meta tag, and this means the Screen Message is now resetting the meta to it prior value after execution, not just blanking it. - or it could be replacing the meta tag in the Message ShowScreen prior to actual display, so the ShowScreen system doesn't actually parse the meta tag for itself in this case) - Still, something to be aware of (and impressed by) with the actual live use and application of this feature.
I continue to be impressed, amazed, and grateful.
>>Sedge