A word used to identify a post with a certain number that marks a milestone on a forum.
A common example is on 4chan
or a similar site where people race to obtain 4MIL GET (4000000th post) or perhaps even 7777777GET.
However, the GET may be either successful, leading it to be enjoyed and commemorated by the community or a failure, leading to posts filled with sage
and general unpopularity.