I saw that on another forum and wondered about it myself. It was stated that you can see all 12 negatives report codes or something and that it was an alternative link to provide revenue to that forum. It looks almost identical to the myfico.com with a few minor exceptions but I didn't dare try to order my reports from it.
Was kinda curious. One of those things that made me just a bit suspicious, but then I do hold to the view that paranoia is merely total awareness.
This myFICO.com/12 site is provided by a company that has an affiliate relationship with myFICO where they link to myFICO.com. The "12 negative factors" refers to the fact that you get 3 reports with (up to) 4 negative factors each, for a total of (up to) 12.
You may have noticed that, from myFICO, the negative factors for Equifax and TransUnion reports incorporate data from your report, i.e. specific revolving utilization percentage, exact number of inquiries, etc., but that the Experian reports only provide "static" text that doesn't contain any data from your report. This is because Experian doesn't allow the use of their data for this purpose.
If you buy your myFICO reports from the affiliate landing page, you'll get this Experian-like static text from all 3 bureaus but may receive more total negative factors, i.e. up to 12. The difference in number of negative factors between myFICO.com and myFICO.com/12 is due to different logic between the two sites where myFICO reports deliver fewer negative factors the higher the score is, with a miximum of the top 4 for a lower score and only the top 1 or 2 for a higher score. Scores over 800 show no negative factors from myFCO.com.
The reason for this myFICO.com format is because, for the higher scores, these factors are less relevant for understanding why your score isn't higher.
So, for example, from myFICO.com you will probably see 4 negative factors on a score in the mid-600's or lower but none on a score over 800. But from myFICO.com/12, you could potentially have have 4 negative factors on a high 700s score as well as a low 600s score.
Either way, all other report and score data is the same regardless of what site you access the reports from. Hope this makes sense.