During the Dallas/SD game the officials flagged the Cowboys for an illegal formation because "number 86 covered up number 83" (or something like that but to any extent it was 2 wide out numbers in the 80's). Why would this make a difference?

Because in the NFL, eligible numbers cannot line up in ineligible positions and ineligible numbers cannot lineup in eligible positions. Exception: if they report in to the Referee, they may line up in that position.

so when 86 covered 83, 83 then became in ineligible reveicer.

Yes, it is technically an illegal substitution for a "player wearing eligible pass receiver numbers participating in an ineligible alignment" of vise versa. Rule 7-2-3-supplamental notes (legal position changes).

So it short, if they are going to have an ineligible number in an eligible position, or vise versa they need to report it to the referee.

OK but wide outs coverup tight ends all the time, why not flag those? If it is a running play, what difference does it make? Just another example of how the NFL fools that never played the game make up rules to have games extended out to get more commercials in to line their pockets I guess.

I'm pretty sure those wide out are off the LOS, as to not cover up the TE.

cowbyfan1, your understanding of why rules are written is truly impressive.

cwboyfan, it matters because that's the rule. And the WR never covers up a TE, unless they told the referee beforehand.

What the hell is that supposed to mean? I've been watching pro ball for about 30 years and have never seen that called. Common sense would dictate that coverage up another receiver or TE would do nothing but make that person ineligable. What advantage is gained by covering him up? I seriously doubt that it is so NFL officials don't have to think about eligable/ineligable as it is too hard for them to understand and figure out.

This was just called in the Chiefs/Raiders game.

No sir, not in the NFL, they don't.

I would say that in previous years they may have been a little more lenient with players lining up in no-man's-land. But this season there seems to be, based on the calls being made, an emphasis on making sure that the eligible receivers are properly aligned.

This is just a guess of mine as I have no information but I can try to get that by Wednesday. I work with the son of the local NFL official on Fridays. Let's just say that the son gets a little more film review and critiqueing than most of us and this is just his second year.