The hashtag as a concept is not new. A hashtag is an index term – like when you look up a word in the back of a book to see where in the book the topic is covered.

You've probably heard the terms metadata, ontology, taxonomy, etc. Back in the 1970s and 1980s, I taught a course every year on this topic to information specialists, as do dozens of other people in information programmes across the country to this day. People in the information business have to select and use indexing vocabularies for databases and have to understand the various theories for the design of these vocabularies to optimise performance.

Now hashtags have not been invented with any indexing theory in mind, as far as I know. They are a part of what are called 'folksonomies', that is, they are terms invented spontaneously by people and reflect an often spur-of-the-moment labelling of the topic of the Tweet.

Marcia J Bates, UCLA Professor Emerita of Information Studies

A patent is a good protection for the 'creator' if they need to invest billions to bring an idea to life. Yet it is monopolising a technology and most of us suffer more than we gain from a monopoly. If Tim Berners-Lee would have gotten a patent for the development of the http protocol, we wouldn't have the internet as we have it today.

Axel Schultze, CEO Society3

For two reasons, primarily: 1. Claiming a government-granted monopoly on the use of hashtags would have likely inhibited their adoption, which was the antithesis of what I was hoping for, which was broad-based adoption and support – across networks and mediums.

2. I had no interest in making money (directly) off hashtags. They are born of the internet, and should be owned by no one. The value and satisfaction I derive from seeing my funny little hack used as widely as it is today is valuable enough for me to be relieved that I had the foresight not to try to lock down this stupidly simple but effective idea.

Chris Messina, creator of the hashtag

Primarily because hashtags are not patentable. The idea is not new; there is 'prior art' dating back more than 20 years. Hashtags are just a modern implementation of an old idea. Another example is the standard internet email address ( format). Email was already in existence using different formats for email addresses (using ! instead of @, etc). So it could not be patented because the idea was not original, only the specific implementation.

Mark Hayden

Why didn't the creator of the hashtag patent the concept? originally appeared on Quora: The best answer to any question. Ask a question, get a great answer. Learn from experts and get insider knowledge. You can follow Quora on TwitterFacebook, and Google+.