Need Translation of Ad

Please forgive such a basic question regarding a tournament advertisment; the ad read as follows:

Open to all U-2300/unr. $(b/20): $105-85, Top U-1800/U-1500 $55 each. EF: $20.

Assume this means open to all unrated under 2300 but the rest is too vague for me. Can someone translate?

Thanks.

I believe the top under 1800 and the top under 1500 stand to win $55 each. The entry fee is $20.

I wonder what $(b/20): $105-85 means.

The top 20 Under 2300 stand to win anywhere from $85 to $105?

And is this rating the same as the one used at Chess.com?

$(b/20) means that prize money is based on a minimum of 20 players entering the tournament. The $105-$85 refers to the prizes for 1st and 2nd place respectively for those above 1800. Top finishers in the U-1800 and the U-1500 sections will receive $55 each.

Total prize money awarded will be:

$105
$ 85
$ 55
$ 55
-----
$300

Based on 20 players paying $20 each, the initial pot will be $400. After paying $300 in prizes, the extra money may be used to pay for the venue or it may be distributed as extra prize money to the winners or they may just put it in the club treasury. Different clubs do it differently.

Your Chess.com rating is different than the one considered for the tournament in question. The tournament directors will refer to your official USCF rating when making section assignments.

If fewer than 20 people enter the tournament, prize money is usually prorated accordingly.

Thanks. I found this at the Chess Center site:

How do I learn about tournaments?Tournaments rated by the USCF are usually advertised in the Tournament Life Announcement section of Chess Life. Most tournaments geared towards young people are also advertised in the back of Chess Life for Kids. Tournaments held in the local area are usually found on the How do I read the Tournament Life Announcements?

The codes used to save space in the Announcements (TLAs) can be quite confusing. Please use this as a reference:

#-SS: Swiss System. The number that precedes "-SS" tells you how many rounds (games) each player will play.

#-RR: Round Robin. A round-robin tournament means each player in a section will play every other player in that section.

TC: Time Control. How much time each player has to avoid being forfeited. “G/30” (also known as action chess) means each player has 30 minutes for the game, so an entire game will last one hour or less; this is the most common time control for scholastic events. “40/2” means that a player must make 40 moves in the first two hours, and then the player receives more time to make additional moves.

Reg: Registration. Players who have not pre-registered must come during the hours specified to sign up for the tournament.

Rds: Tells you what time the games will start.

EF: Entry Fee.

$$: Prizes (G, under prizes, means Guaranteed, as opposed to b/#, which means based on a certain number of entries.)

NS NC W: No Smoking, Computers may not play, Wheelchair accessible.

Ent: Advanced registration should be sent to the person listed.

One other question: what does "GPP: 100 Enhanced" or "GPP 6" mean?

I have the same question.