Generic Setting

Generic Locations are the result of the Suethor not bothering to remember a canon location or create a new one with any detail, or just plain not having a location mentioned. Classic example are the random forest where a Sue appears and either saves the main characters or is saved by them, the location of the vampire clan/wolf pack/secret school of Sues/Fenrir Greyback's little brother's family/ mafia don who raises Harry instead of the Dursleys, and the place where Fire Emblem characters suddenly decide, against all evidence in canon, that they're in love. Fanon Death Eater meetings are often held in poorly-lit Generic Locations.

As Generic Locations almost always contain Mary Sues, Agents following canon characters through Generic Locations are advised to be ready for an ambush.

Anyone with any creative inclination can make changes to a Generic Location. This includes PPC agents on a mission. Often to the annoyance of their partner.

Generic Setting
The Generic Setting of a location is the normal state of that location in badfic. For instance, Rivendell's Generic Setting is during or a few days before or after the Council of Elrond, and the Generic Setting of the Great Hall of Hogwarts is a feast. It should be noted that Generic Settings can sometimes be naturally dangerous; for instance, the Generic Setting of Severus Snape's bed contains a Sue or Stu (possibly more than one, if the author pushes things).