Some abbreviations have different words use but it is all about opinion. For example, IMHO which others might interpret this abbreviation as IN MY HONEST OPINION or IN MY HUMBLE OPINION. Some may interpret OP as original post, original poster, open post. There are some people might made another abbreviation which is IMOO that stands for IN MY OWN OPINION.

These are the abbreviations that some are mentioned in the previous post which is used only on signature campaigns.