Your bill sounds like it might have a "flipover" error. My advice would be to have it examined in person by someone who deals with error currency because auction values can exceed $300.
Bills are printed in multiple steps on large sheets of paper. A flipover error can happen if someone accidentally feeds a sheet in the press upside-down and/or backwards.
No mint mark means the coin was minted in Philadelphia.
1928 $2 bills were issued in 8 different series variations identified by a small letter (or its absence) near the date. Please check for the letter, then see the question "What is the value of a 1928 [letter] US 2 dollar bill?" for more information. The red seal and serial numbers simply mean that the bill is a United States Note, a form of currency that was printed up till the 1960s.
50.00
Serial numbers are counters and a security feature but usually don't help to ID a bill for valuation. Please post a new, separate question with the bill's date and what letter if any is next to the date. Some collectors will pay extra for numbers with a special pattern, e.g. 12345678, or low numbers such as 00000015.
The big letter to the left of Washington's portrait indicates the Federal Reserve branch where the bill was originally distributed. The same letter is found at the beginning of the serial number. The last letter indicates how many runs of serial numbers have been used, where A is the first, B is second, and so on. Then there will be a tiny letter and number, such as J5 or FW D191, which is the plate position during printing.
rill
braveryconvictconvertconventconvenecravingdrivingdriversflavorsfervourgravelyheavingleavingmarvelspreventserviceprovingsolvingslavingsalvageshavingsurvivetrivialtravelsweaving
it means crazy
reversed
It is written before numbers and it is a capital "S" with one or two lines from top to bottom of the letter.
Ibuprofin
reversed
The Equate cough drop are imprinted with the B because the are made by BestSweets, INC. Thus baring the B to represent the company that makes them.
It is upside down and reversed.
You must have a signed or imprinted merchant credit card copy to provide when answering a dispute.
Serial numbers can't readily be used to ID a bill.Please post a new question with its date, seal color, and whether there's a small letter next to the date.
Serial numbers are counters and a security feature but rarely affect a bill's value. Please check your bill's denomination, date, and what letter if any is next to the date, then enter the question "What is the value of a (date) US (denom & letter) dollar silver certificate?" - for ex. "What is the value of a 1934 D US 5 dollar silver certificate?" Some collectors will pay extra for numbers with a special pattern, e.g. 12345678, or low numbers such as 00000015.