These are abbreviations in 'email speak'. IMO means In my opinion...LOL means laugh out loud.....any time you see one,ask what it means. It only takes a little while and you'll know them all! There is a list of the abbreviations somewhere,but I can't remember where. I'm sure someone else can tell you..
Have fun with it..
Thank you wildrose for asking the question and thank you magicmom50 for answering. I too have been wondering ever since I discovered the message area of the Cruise@ddicts and Cruise Critic. It sure helps to know what the abbreviations mean.