As is the case for all other lists, the "Honor System" applies.
The Northeast 4000 Footer Grid abides by the original 'Underhill' rules for the bagging of official peaks on the various 4000 footer lists.
An official peak is a peak that is counted once on a hike from the beginning trailhead to the finish trailhead. Even though it may be passed over more than once in the course of the hike, it should be counted only once.
On a backpack trip, a peak can be counted once only. Unless
of course, the backpacker goes all the way down to a legal
vehicle trailhead, and turns around, and goes back. Or, goes
back, via another legal vehicle trailhead and trail.
On a backpack trip, the date the summit is touched, on the
initial pass over, is the "OFFICIAL" summit date.
"All four seasons at Baxter State Park." For the purpose of
the "grid", all remote trailheads, Chimney Pond, Roaring
Brook, Abol Stream, Katahdin Stream, Nesawadnehunk,
Daicey Pond, Kidney Pond, etc., are considered to be
legitimate day hike trailheads.
A hike from any of these locations on a Monday, and
repeated, again, on Tuesday, to the same summit or
summits, can be considered two separate hikes, on two
separate days, and can be claimed twice.