What does HMU stand for?

Does HMU mean “Hydrogen manufacturing unit”?
Could be, but not very often. Much more likely this abbreviation would mean something different. So, when you see HMU, or hmu (both uppercase or lowercase versions actually mean the same thing) while communicating with someone in the Net you might think: “Lord, what does hmu stand for?” The answer is quite simple: HMU stands for “Hit Me Up”, or, in other words “contact me”, “call me”, “text me”. By sending you a HMU acronym the person whom you are corresponding with is indicating his (or her) desire to get together with you at a later date if you want to do so. Nowdays when people are lazy, or let us say are not willing to waste their time such shorthand way to invite someone to further communication becomes quite popular. Using HMU abbreviation gives people an opportunity to avoid typing long phrases such as “I do not mind if you phone me later” or “do not hesitate to contact me somewhere in the future”. As was said above, using uppercase or lowercase versions (HMU or hmu) is correct for both. However, it is recommended, that you should avoid typing entire sentences in uppercase. Due to unwritten rules of modern online communications, phrases that are typed in capital letters are usually associated with rude shouting. To give more understanding of HMU meaning for those who still remember good old times there is one more hint. HMU to a certain extent sounds something like “Roger” in radio communication conducted in simplex mode. While “Over” quite naturally means that the conversation is finished, full stop, “Roger” for some reason indicates that communication is still in progress. It worth remembering though, that HMU (as well as “Roger”) goes to a category of slang words and abbreviations. Having had explained above in details what does HMU stand for, we still cannot say that it is the end of a story. Understanding of what this modern online “shibboleth” means is only half of the deal. The other important thing is how to respond to it if you don’t want to be impolite or misunderstood. It is especially important for online communication when you do not actually see your conversation partner and for that reason you cannot react immediately if something was said in a wrong way. Quite often just one improper word or phrase could “kill” communication at all. So, what way to react when you receive an HMU from a sender would be the best or, at least would not be the worst? There are no any special words or phrases that are commonly accepted or prescribed for the situation like that. No there exists any specific abbreviation that you should or recommended to send in return. The one and only thing that you should never do after receiving HMU from anyone, is to ignore it. It is true of course only if you do not want to break a contact with this person. So, if you do not mind having communication with your conversation partner in the future, then you are recommended to show your interest in the matter. Of course, it is your right to decide whether you are going ahead with this contact or you are not. Do not forget though, especially when communicating in social network or on internet sites, when all what you post is open and seen by others, that ignoring HMU message is considered to be a rude behavior in the vast majority of social groups. That is why in any case you would better to reply even if you are not interested in further communication. And if you still are, then ideally you should reply in the same day as you have received a HMU “invitation” so that to really “hit up” your conversation partner.