Dipford (also known as Dipauthor) is the incestuous shipping of Stanford Pines and Dipper Pines.
Prior to the reveal and character debut of Stanford Pines, Dipper was clearly obsessed with the author of the journals, idolizing a person he didn't even know and doing anything to seek him out. A very small, underground fanbase for this ship was formed on Dipper's obsession, his infatuation being translated into unyielding obedience, lust or romantic feelings.
Although previous fans of Dipford jumped ship when it was revealed that Dipper and The Author are related and have a huge age gap between them, other shippers were not deterred, and a small fanbase still remains to this day.
Dipper's fascination with his great uncle is commonly shown developing into a crush -- one that is either purely innocent or one that awakens sexual urges as well. While in most instances Dipper is filled with shame and knows his feelings are immoral, he is also depicted being so intoxicated with these feelings and his need to worship or 'please' his hero that he disregards the fact that they're related and Ford has many years on him. Ford is either shown rejecting his nephew's feelings, returning them and feeling ashamed for it, or reciprocating and maintaining a (rather taboo) romantic/sexual relationship with Dipper.
In fan-fiction, the ship requently follows a sexual dubcon theme, where either Dipper forces himself on Ford, or Ford takes advantage of Dipper sexually. Guilt and shame are also common themes in Dipford fan-fiction.