Hi Phillip -
I apologize that we don't have more standard language for the incoming text messages. Even within the API program we have a few different terms...
The official term is 'MO' for mobile originated.
We also call then incoming, inbound, and sometimes in the API context we refer to them as 'callback' or 'webhook', which is really the relevant aspect for you.
We only change you if we get a 'MO' in from the carrier, which matches the shortcode (343434) and has your keyword (or aliases) in the first two words of the first line. That's basically what we use to match the MO to your account, and then do a callback to the URL you have specified (if you did specify one in the developer dashboard).
So - if your keyword is 'memorial' then anytime someone out there texts 'memorial' to 343434 we'll think it's yours, and charge you.
If there was a situation where that was in error, (and you wanted to stop the inbound MOs) then we can take care of that, just contact me and we'll block that user.
Hope that helps!
ATR
Anthony Rossano, Technologist