there is no rule saying you can’t have 9 on the line. in fact, you can have 10 if you want. only rule saying anything about numbers says you have to have at least 7 on the line. center has to snap the ball to someone, so that someone is literally the only person required to be in the backfield. by rule, any player lined up on the LOS is considered a lineman. so in this particular situation, for the sake of the rule, those receivers are considered lineman. if any part of the WR (typically his head or shoulders) break a plane trough center’s hip, he is on the line. there is no rule that requires the tackle to be covered. in order to run a route, he has to report as eligible. so technically he is an ineligible receiver in this formation. but that only becomes a penalty if he goes downfield, which he did not. we definitely got the shaft on multiple calls. this particular call, they got right.
you missed my second post where i said he has to be covered or declare as eligible (which wasn't announced over the P.A.)... by rule an undeclared lineman can not be the leftmost or right most player on the los... that's why when teams bring in their jumbo packages with extra linemen, you hear an announcement that so-and-so is declaring as an eligible receiver... this is strictly to cover the tackle(s) from being on the end of the line... so unless they announce that the left tackle in the picture has declared as an eligible receiver, he is in fact, ineligible and therefore illegal...
he only becomes ineligible once he goes down field. it’s not illegal to line up that way. you can line him up by himself off in space if you want to. it’s illegal for him to go downfield. here is the entire rule about pre-snap formation here is the rule about eligible receivers: here is the entire rule about ineligible down field: there is absolutely nothing in NCAA rule book saying he needs to be “covered” or “announced” it only becomes a penalty if he goes downfield. here is a link to the entire rule book if you want to look for yourself. http://www.ncaapublications.com/productdownloads/FR17updated.pdf
Pre-snap, it is deemed illegal formation if he is not covered by an eligible receiver... so if there is no need to announce a "tackle eligible" why do they announce it... from the rule book you posted;
you left out the paragraph immediately preceeding your screenshot: the condition you underlined only pertains to a scrimmage kick. this was not a scrimmage kick, so these conditions do not apply. as far as announcing, that’s an NFL thing.
i'll have to defer (don't have time to keep looking through the book), but i watch a lot of football and maybe it's a college only rule (doubt it)... there's a game on tonight... pay attention to how many time you see 1) more than 7 guys on the line of scrimmage or 4 in the backfield and 2) a tackle not covered on the end of the line by a wr, te or declare eligible so as not to be covered...
here, i’ll do the work for you: College rule on formations (same as posted above) “no more than 4 may be backs”. meaning at least 7 on line, but can have more if you choose. no mention of WHERE they must line up in relation to each other on the line. NFL rule: worded different, but still says 7 or more on line. however, it also specifically states that your two ends must be eligible receivers. so in the NFL, yeah this formation is illegal. in college, it is within the rules.