I have a script that calls the function "nlapiGetWebContainer" but when I look in "Help > SuiteCloud > SuiteScript > SuiteScript API - Alphabetized Index" I can't find the function. Does anyone know about this one?

It's in the Commerce API. SuiteAnswers 44300 gets you started and there's also a pdf in the user guide section of help center called SuiteCommerce APIs.

thanks!