A developer found the references inside a hidden file that lists all supported iOS 7 devices.
According to the provided information, Apple is considering three new iPad mini models: iPad “2,8,” iPad “2,9,” and iPad “2,10.” The respective code names for the devices are J75, J76, and J77. This points to one WiFi-only model and two cellular-compatible models (just like the current iPad minis). The internal nomenclature for these iPads follows the current iPad minis, which are iPad “2,5,” iPad “2,6,” and iPad “2,7.”
The document says the new iPad minis will feature a s5l8950x processor which is the same A6 chip used in the iPhone 5. Unfortunately, it appears the new iPads minis referenced do not include "@2x" hooks to higher resolution images. This suggests that perhaps they do not have a Retina display.
9to5Mac notes that "perhaps corroborating this is that the rumored Retina display iPad mini codename is 'J85,' while the iPad mini model we have learned about is 'J75'."
DigiTimes recently reported that Apple will release a slightly updated iPad mini this year but won't release a Retina display iPad mini until 2014. However, that report was followed up by another that said LG was making headway in producing Retina displays for the iPad mini. It's seems unlikely that Apple would launch a new iPad mini with a display that inferior to its rivals. Google just released a new Nexus 7 tablet that features a 1920 x 1200 HD display (323 ppi).