You have only 30 minutes, yes, thirty minutes to edit, modify or remove your post after posting. Period.
After that, you must ask a mod or the FA if you need a post modified or removed,and you must provide a compelling reason to waste our time doing so. Period.
There IS a "preview" feature which allowes you to preview your post BEFORE it gets posted, so you can check for spelling or formatting errors and we STRONGLY URGE YOU TO USE THE PREVIEW BUTTON.
You are equally strongly urged to THINK BEFORE YOU POST!