These are the following Do's and Don'ts for happy posting at PsB.

Do
Do use the search.
Please try to be descriptive with your problem.
Use a topic title that has some meaning to your issue.
Be considerate to others, DON'T SHOUT, TrIpPy CAsE UsaGE iS NOt CoOl, Capitalising Each Word Is Difficult To Read.
Try to remember that not everyones first language is English. Keep this in mind before going off on one.

Don't
Don't post cheats, cheat names or links to cheat sites.
Don't be abusive.
Don't flame.
Don't use racist/sexist or otherwise inappropriate language.
Don't swear. Apparently kids sometimes hang here. (we'll ignore the fact these same kids probably know more swear words than all us oldies put together)
Don't accuse people/clans of cheating without proof. Unsubstantiated claims like this lead to flames and get nowhere.
Don't post innocent players GUIDs. Same also goes for cheats who are not yet on the MBL.
Don't re-open Moderator/Staff closed topics, they get closed for a reason and the reason is normally posted.
Don't dig up dead topics from months ago, start a new topic and link to them instead.

Others
When posting PunkBuster Screenshots only post PNG format images. Do NOT post JPG files.
When posting PunkBuster Screenshots, remove the GUID and Alias.
When posting MD5 Tool entries, remove the names of the cheat files.