>>Has>>>[1] Since AppleScript is a weakly, dynamically typed language, the only time it can know for sure what 'year' (as in 'year of <something>') means is when it actually applies it to an object at runtime. However, in order to create its English-like appearance, it makes a best-guess about the user's intent for that word according to where it appears in the script: if it appears within the 'tell app "iTunes"' block, it gives it one meaning; if it appears outside the block it gives it another. If it guesses wrong, the script fails at runtime.
All this is sort of true, but most of it applies only when there is a terminology conflict, which is remarkably rare, even without the watchful eye of the apple event registrar.
I say sort of because it's not really a guess. When the compiler interprets a command inside a tell, it starts looking in the application dictionary, and if it finds a match it compiles and does not go on to the next level. So it's not really guess work, it makes an assumption, it consistently makes the same assumption, and if there is a conflict, the compiler never really knows because it stops looking as soon as it hits a match.
In most cases, this is kind of cool. If you're going to make a new folder in Finder or a box in Quark or a message in mail, you type the same keyword and depending on what tell block you're in the compiler figures out the command you want. But the scripter is in control, if you want to make a new Quark text box you wouldn't put the command inside a finder tell.
And how many terminology conflicts are out there, anyway?
It's like making cooking for six before you've even sent out the dinner invitations and have no actual idea if two, five or ten people will be coming.