Jim Tripp recently wrote a tour de force list of what NT can mean. Non-targeted input can mean:
(1) going in without a plan and winging it.
(2) putting the message before the language.
(3) keeping input comprehensible by sheltering, not targeting.
(4) massed reps over time versus input flood.
(5) in assessment, recognizing that variations will exist in what gets picked up and when by individual students.
My definition is something along the lines of making the message greater in importance to any curricular needs attached to lists like backwards planning for novel lists, high frequency vocabulary lists, thematic unit lists, etc.
I guess it’s all of the above things. However we define it, it works better for some teachers than targets do. To each his own preference….