No advertising, this includes "Free stuff for your whatever" type posts, even if you didn't write the post.
Posts must be about things businesses are doing. Posts that are nothing more than long writeups with links to things that "help your business" or explain "why you need this for your business" are advertising and fall under rule #1.
Keep memes and image posts on topic for what businesses are doing.
You're free to talk about what you've done in making your personal business a success, but talk about it in general terms. Don't give product names, pictures, or any kind of links.
Start at #1 and read the rules again.

Posts that are amusingly bad may be moved to and deemed "Coke." Batteries are not included, this offer void where prohibited by law, which is pretty much everywhere including the moon, Mars, and specifically exoplanet GA3-701 where it is punishable by a fine of not less than 15²⁸ stimborbs and 376 solar years in prison. No cash value save that which is in your pants pockets and will need to be given to us. By using this sub, you offer control of your eternal soul to stupidbird who may use it for whatever purposes, up to and including the dark arts in which case your only recourse is to appeal to the council of evil and have your petition denied. Birds are not real. We’ll decide what will be on the contract. You’ll pay us to be allowed to do the work. You will make the product. Then you’ll give it to us, and it will be ours forever. If anybody buys it, we might give you some money. If you’re lucky. Or we might put it in a drawer and forget about it. In any event you will get nothing, and you will thank us for it. This isn't the algorithm, it is close. You understand that any breach of this agreement will invoke unspecified consequences of a dire nature, potentially affecting your being in ways beyond your comprehension. Proceed at your own peril. We've increased your synergy, but this sub cannot save you money if you own a parakeet. Parakeets are not real. All posts here are for informational purposes only and should not be taken as business or medical advice. Supplies are limited, this offer void after January 1, 1922 or when supplies are exhausted. Please put that down, don't stick that in there, and for the love of god please put on some pants, no one wants to see that. (c) 1988 Con-Troll, Inc, PO Box 12, Wrestlemania, MN.